Discuss Which is the more powerful pump? in the UK Plumbing Forum | Plumbing Advice area at PlumbersForums.net

Balancing should be the last thing to do IMO.
Can you just run on DHW and check values as this is practically a short circuit through the cylinder coil where most of the short? run will/should be in 22mm, if there is a balancing gate valve on the coil return, just open it fully.
I would expect to see ~ 34W on CC3.
I will call for hot water as the( data term) will allow me to press for one shot hot water the "Y" plan valve should close the heating down and open the hot water circuit up, if that does not work are the Alpha 3 and the Alpha 2 exactly the same apart from the control panel if so Instead of going down the road of taking the Alpha 3 out I could just change the heads and see what that does
 
Balancing should be the last thing to do IMO.
Can you just run on DHW and check values as this is practically a short circuit through the cylinder coil where most of the short? run will/should be in 22mm, if there is a balancing gate valve on the coil return, just open it fully.
I would expect to see ~ 34W on CC3.
Hi John I called for hot water and it immediately went up to 34 watts and the flow rate went up to 0.6m3/h
 
Hi John I called for hot water and it immediately went up to 34 watts and the flow rate went up to 0.6m3/h
So when the hot water reached it's temperature the "Y" plan valve closed the hot water circuit and opened the rad circuit the wattage went back to 15 flowrate 0.0m3/h, so I opened the lockshield valves on the towel rails and the wattage went back up to 34watts and the flow rate up to 0.6m3/h what would take that to mean?
 
Hi John I called for hot water and it immediately went up to 34 watts and the flow rate went up to 0.6m3/h
That points to something else rather than a pump problem, once the pump reaches max power then it will only display 0.6M3/hr, but it could be pumping 1M3/hr @ 5M or 1.5M3/hr @ 4M and so on depending on pipe/coil friction losses.


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So when the hot water reached it's temperature the "Y" plan valve closed the hot water circuit and opened the rad circuit the wattage went back to 15 flowrate 0.0m3/h, so I opened the lockshield valves on the towel rails and the wattage went back up to 34watts and the flow rate up to 0.6m3/h what would take that to mean?
It would mean that there is no real restrictions in the upstairs pipe work.
Can you ensure all d/stair rad valves including lockshields are fully open, then shut all upstairs (one valve on each rad will do) then take pump values on d/stairs only.
 
Right opened all the rads downstairs no change, still 34 watts, closed off both bedrooms again no change still 34watts, but as soon as I touched the towel rails the wattage went down to 16 flowrate 0.0m3/h, any suggestions?
the wattage is back up to 22 watts but the flow rate remains at 0.0m3/h
 
the wattage is back up to 22 watts but the flow rate remains at 0.0m3/h
Hi john just been looking at the dates I bought the towel rails and the Alpha 3:- bought the rails on the 23/6/2021, I can remember I had problems when I plumbed them in so finished the job (after set backs of one sort or another) 2 months later, bought the Alpha 3 on the 27/4/2022 but that was after we had been away on holiday, so between finishing the rail installs and noticing that the heating was'nt working as well was about 4 months, everything seems to stem from when I put in the towel rails, just wondered if I have done something wrong will have to check to find out but we are going away again in our caravan so probably won't do that until we come back, what do you think? open to suggestions, or a slap on the wrists!
 
Right opened all the rads downstairs no change, still 34 watts, closed off both bedrooms again no change still 34watts, but as soon as I touched the towel rails the wattage went down to 16 flowrate 0.0m3/h, any suggestions?
So, how many rads open d/stairs when all u/stairs rads + towel rads shut off when flow fell to zero??.
If you reopen just one towel rad does the flow increase?
Normally, even if only one rad open fully would expect a flowrate of - 0.3 m3/hrs and a pump power of - 25/26W on CC3.
 
So, how many rads open d/stairs when all u/stairs rads + towel rads shut off when flow fell to zero??.
If you reopen just one towel rad does the flow increase?
Normally, even if only one rad open fully would expect a flowrate of - 0.3 m3/hrs and a pump power of - 25/26W on CC3.
Hi john there are 3 rads downstairs each one on it's own drop, when I shut off the bedroom rads there was no change to the wattage :- 34 and no change to the flow :- 0.6m3/h ( both valves on each towel rail were fully open) as soon as I touched either the lockshield or the on/off valve on either towel rail the wattage went down to 22 watts and the flow went down to 0.0 m3/h it's got me thinking that there is a problem with the pipework to or from the towel rails, if I have to alter the pipe work I can get at the flow from the "Y" plan valve and increase it to 22mm (it's 15mm at the present) and take it all the way into the bedroom to where the first drop is to the big rad in the sitting room then it would be 15mm after that as I cannot get at access after that
 
Hi john there are 3 rads downstairs each one on it's own drop, when I shut off the bedroom rads there was no change to the wattage :- 34 and no change to the flow :- 0.6m3/h ( both valves on each towel rail were fully open) as soon as I touched either the lockshield or the on/off valve on either towel rail the wattage went down to 22 watts and the flow went down to 0.0 m3/h it's got me thinking that there is a problem with the pipework to or from the towel rails, if I have to alter the pipe work I can get at the flow from the "Y" plan valve and increase it to 22mm (it's 15mm at the present) and take it all the way into the bedroom to where the first drop is to the big rad in the sitting room then it would be 15mm after that as I cannot get at access after that
I was just thinking that as the towel rails were fully open, and the bedroom rads closed and there was no change to the figures, as soon as I touched either valve on the towel rails I was virtually shutting off the flow because the pump cannot pump down the drops and back up again to the boiler, I don't know I might be clutching at straws
 
Looks that way alright, you my have both towel rads in series and the return tied back into the flow, a one pipe system in effect, if you run them again with both opened and the 3 d/stairs opened as well then the flow temperature into the 3 rad may be just lukewarm as it will/could be now the return temperature from both Towel rads?.
 
Looks that way alright, you my have both towel rads in series and the return tied back into the flow, a one pipe system in effect, if you run them again with both opened and the 3 d/stairs opened as well then the flow temperature into the 3 rad may be just lukewarm as it will/could be now the return temperature from both Towel rads?.
Hi John I have a few jobs to do to be able to lift part of the bathroom floor up again but as soon as I have had a chance I will get back to you with the outcome.
 
Hi John I have a few jobs to do to be able to lift part of the bathroom floor up again but as soon as I have had a chance I will get back to you with the outcome.
One thing John would 15mm piping have the same effect if so I am going to try and get most of the accessible runs redone in 22mm pipe and see if that improves the matter, will have to live in our caravan on the drive till I get it done.
 
15mm piping would require - 4.5 M head IMO to circulate 20LPM assuming total rad output of 20kw, if main pipework is 22Mm then a 2.5M head would probably suffice so see what the piping problem is first and you can decide then maybe to renew some sectios in 22mm but the 15mm is certainly not the cause of your present problem
 
15mm piping would require - 4.5 M head IMO to circulate 20LPM assuming total rad output of 20kw, if main pipework is 22Mm then a 2.5M head would probably suffice so see what the piping problem is first and you can decide then maybe to renew some sectios in 22mm but the 15mm is certainly not the cause of your present problem
Hi John, notice the time, I cannot sleep I am thinking constantly about this problem, thought of this, once I have checked the pipework for the 2 towel rails in the bathroom (that is where the problem lies I think) and done the necessary work, if I disconnect the heating pipe from the "Y" plan valve, blanked the valve off and put a drain hose on the heating pipe, isolated the pump so no water can come through the pump, the only way water can get into the boiler is through the filling loop, as the "Y" plan valve is blanked off no water can back flow through the hot water tank. If I then shut off all the flow valves on all the rads turn on the filling loop the boiler will fill up and the only way water can get to each rad is through the boiler via the return pipe, as all the flow valves are shut off the return pipe on each rad is now acting as a flow agreed so far? Now if I open the flow valve on the rad furthest from the boiler the water will flow through that rad and out of the drain hose I connected to the heating pipe I disconnected from the "Y" plan valve thus flushing out that rad and section of the heating system. If I then shut off that flow valve on that rad and opened the flow valve on the next furthest rad away from the boiler it will do the same as before. I can now do exactly the same for each rad until I get back to the nearest rad to the boiler, this will I hope ensure that there is no restriction in the pipework and also flushing the system out. If I then close the filling loop the pressure in the system should return to "0" as the drain pipe is still connected, if I disconnect the drain from the heating pipe the system should be filled to the height of the "Y" plan valve, so from that I can say that the downstairs would be filled and the upstairs filled to the height of the valve ie halfway up each upstairs rads, would you agree so far? I then reconnect the heating pipe to the "Y" plan valve and begin to fill up the system via the filling loop as all the rads are still shut off and the nearest rad to the boiler is open any air can only go to that rad so I vent it and then open up all the rads and fill them, having done all that the pump, as there should be no restrictions in the pipework, should be able to pump water through the whole system, if it cannot then I can assume the pump is not strong enough or I can put a stick of dynamite in the boiler and blow the whole thing to kingdom come I am that "P £ $ % & D off with the whole situation and go and live in our caravan in the back garden. I am ever so sorry for boring the pants off you and thank you very much for all the help you have given me, all the best Ken
 
I'll have a look at the above later on but you can see if pipework, (at least the main d/stairs flow/return) is free if you do the following before addressing the towel rad problems.

Shut off the upstairs, ensure all downstairs rads open fully, run the pump in the following 3 modes, CC3, CP1, CP2 &CP3 and note the pump values, then do the same tests with the two towel rads only and post your results, it will only take a few minutes to do these tests.

Also, please post the outputs (kw) or dimensions of the rads, including towel rads and their locations.

The main job is to fix your pipework and everything else can be decided then.

Edit, 3 modes are CC3, CP2 and CP3.
 
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This might put your mind a bit more at ease until you actually see what's what.

I am assuming that there are two rads in series and in series then with the flow or return main piping, you would then have 4 very small valves in series which are designed only for flowrates sufficient for say a 3 kw rad, you can see below that the head loss is only 0.65M with a 3kw rad or 1.8M in the very unlikely event that you have a 5kw rad. With 2 rads in series the head loss is 3.6M @ 5kw/5LPM so if installed in the main flow/return then nothing left for pipeline losses etc.?.

So get your floor up ASAP.

1662123825515.png
 
This might put your mind a bit more at ease until you actually see what's what.

I am assuming that there are two rads in series and in series then with the flow or return main piping, you would then have 4 very small valves in series which are designed only for flowrates sufficient for say a 3 kw rad, you can see below that the head loss is only 0.65M with a 3kw rad or 1.8M in the very unlikely event that you have a 5kw rad. With 2 rads in series the head loss is 3.6M @ 5kw/5LPM so if installed in the main flow/return then nothing left for pipeline losses etc.?.

So get your floor up ASAP.

View attachment 77372
Hi john have checked all the pipework and everything seems to be ok in theory, there could be a "bit of a traffic jam" where the returns go back to the boiler but the only way I could alleviate that would be to incorporate swept "T"s in the return lines from the towel rails,
 
Hi John I have been a bit busy today but will do the tests tomorrow and get the results off to you also the kw of each of the rads
Very good, thanks.
Hi john have checked all the pipework and everything seems to be ok in theory, there could be a "bit of a traffic jam" where the returns go back to the boiler but the only way I could alleviate that would be to incorporate swept "T"s in the return lines from the towel rails,
The plot thickens!
Hi john there are 3 rads downstairs each one on it's own drop, when I shut off the bedroom rads there was no change to the wattage :- 34 and no change to the flow :- 0.6m3/h ( both valves on each towel rail were fully open) as soon as I touched either the lockshield or the on/off valve on either towel rail the wattage went down to 22 watts and the flow went down to 0.0 m3/h it's got me thinking that there is a problem with the pipework to or from the towel rails, if I have to alter the pipe work I can get at the flow from the "Y" plan valve and increase it to 22mm (it's 15mm at the present) and take it all the way into the bedroom to where the first drop is to the big rad in the sitting room then it would be 15mm after that as I cannot get at access after that
Can you verify/clarify the above.

With bedroom, Upstairs?,rads shut off, you get 34W/0.6m3/hr through the Towel rads + (maybe) the downstairs rads but if you close any one of the towel rads then 22W/0.0m3/hr.

Can or have you tried shutting the downstairs rads, opening the bedroom rads + the towel rads and note the values.
Then shut shut the towel rad(s) valves and note the values, ie with the bedroom rads only open.

Also can you see/show where the expansion vessel is tied in to the system.

A simple line diagram might show up something.
 
Very good, thanks.

The plot thickens!

Can you verify/clarify the above.

With bedroom, Upstairs?,rads shut off, you get 34W/0.6m3/hr through the Towel rads + (maybe) the downstairs rads but if you close any one of the towel rads then 22W/0.0m3/hr.

Can or have you tried shutting the downstairs rads, opening the bedroom rads + the towel rads and note the values.
Then shut shut the towel rad(s) valves and note the values, ie with the bedroom rads only open.

Also can you see/show where the expansion vessel is tied in to the system.

A simple line diagram might show up something.
Hi John I have made a line drawing of how the towel rails are plumbed into the system as you can see theoretically it is ok, where I have ringed the drawing could possibly be a "traffic jam back to the boiler" and as I said the only way to alleviate the problem would be to replace the "T" pieces with swept "T"s ?
IMG_20220903_085456.jpg
 
Changing the Tees would make no difference IMO.
If you shut off the towel rad or rads does the front bedroom still heat up? and the other 2? bedrooms and what are the pump values?.
 
I'll have a look at the above later on but you can see if pipework, (at least the main d/stairs flow/return) is free if you do the following before addressing the towel rad problems.

Shut off the upstairs, ensure all downstairs rads open fully, run the pump in the following 3 modes, CC3, CP1, CP2 &CP3 and note the pump values, then do the same tests with the two towel rads only and post your results, it will only take a few minutes to do these tests.

Also, please post the outputs (kw) or dimensions of the rads, including towel rads and their locations.mm

The main job is to fix your pipework and everything else can be decided then.

Edit, 3 modes are CC3, CP2 and CP3.
Hi John here are the rad output wattages :- towel rail 1700 x 700mm 668w bathroom
towel rail 600 x 550mm 221w bathroom
flat panel 1800 x 500mm 752w front bedroom
flat panel 1500 x 500mm 626w back bedroom
flat panel 1100 x 500mm 459w entrance
flat panel 1100 x500 mm 459w kitchen
double panel 2400 x 600mm 4485w
the position on the system is as follows :- small towel rail 1
large towel rail 2
kitchen 3 :- on drop
entrance 4 :- on drop
front bedroom 5
back bedroom 6
sitting room 7 :- on drop

when the system was an open vented one it had the vent running up into the loft back to the filling tank, when the plumber put in the new boiler he cut the vent in the loft and attached the expansion vessel to it, pump values to come.
 
What is the expansion vessel pressure and where is it displayed?, is there any pressure display on the boiler.
Does that converted vent go back to the boiler?.

Those rad outputs are incorrect in some cases a 1100X500 rad output is 1265watts and a 1500X500 is 1568watts, a 1700x700 would be roughly 2000watts.
I can figure most of them out anyhow, do they include all the house rads?.
 
I get a total rad output of 12435W but you seem to have omitted the dining room, if you assume another double 2400X600 rad , 4485W, then the total is 16920W or say 17kw, no problem for a alpha3 as the circulation flow required is 24.4LPM @ a 10C dT and 16.2LPM @ a 15C dT. which equals pump heads of 4.2m & 5.2M respectively on CC3.
 
What is the expansion vessel pressure and where is it displayed?, is there any pressure display on the boiler.
Does that converted vent go back to the boiler?.

Those rad outputs are incorrect in some cases a 1100X500 rad output is 1265watts and a 1500X500 is 1568watts, a 1700x700 would be roughly 2000watts.
I can figure most of them out anyhow, do they include all the house rads?.
the rad outputs are as stated the outputs that you have given does relate to the values I have not watts but btu's, I take it that the expansion vessel is the red tank that is connected to the mains to fill the system, I got where it was connected wrong the vent was in fact capped off and it was connected to the feed from the filler tank, the pressure that that is showing is about 1 bar and is on a gauge on the top of the vessel there is no pressure gauge on the boiler and that is all the rads in the house.
 
The values I have given are in watts, to convert to Btu, X 3.412, ie a 1800X500 single is 1881watts (you have 752W) or 6,418Btu, anyhow your total output as you have included all the rads is 12,435watts or 12.44kw so even less of a problem as the flowrates respectively now for 10C & 15C dTs are 17.83LPM & 11.89LPM.

Can you just post a photo of that E.vessel and also showing where its connected into the system, you say it is connected into the cold feed from the filler (feed & expansion) tank, so this tank is now redundant?.

OK, can you just clear this up once and for all .

If all the rads are opened up, including the towel rads, what rads heat up? (also pump values0
If all the rads are opened up, and you shut off one Towel rad , what rads now heat up? (also pump values0
If all the rads are opened up, and you close off two Towel rads, what rads now heat up? (also pump values)
 
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The values I have given are in watts, to convert to Btu, X 3.412, ie a 1800X500 single is 1881watts (you have 752W) or 6,418Btu, anyhow your total output as you have included all the rads is 12,435watts or 12.44kw so even less of a problem as the flowrates respectively now for 10C & 15C dTs are 17.83LPM & 11.89LPM.

Can you just post a photo of that E.vessel and also showing where its connected into the system, you say it is connected into the cold feed from the filler (feed & expansion) tank, so this tank is now redundant?.

OK, can you just clear this up once and for all .

If all the rads are opened up, including the towel rads, what rads heat up? (also pump values0
If all the rads are opened up, and you shut off one Towel rad , what rads now heat up? (also pump values0
If all the rads are opened up, and you close off two Towel rads, what rads now heat up? (also pump values)
in the old system ie open vented "Y" plan, the old boiler (Ferroli Roma which I put in many years ago) was fed from a small open tank in the loft and a vent from the flow went up the wall and was positioned over this small tank (this tank was removed when the new Worcester 15 Ri was put in) the old vent was cut off and capped. The old cold feed to the old boiler was cut in the loft and the expansion vessel connected to it, the expansion vessel was connected to a mains feed of 15mm dia via a pressure gauge. If all the rads and the towel rails are fully opened pump values are 34w and 0.6 m3/h and towel rads are hot, back bedroom hot, front bedroom luke warm, entrance cold, sitting room cold, kitchen just off cold. Shut off small towel rad large towel rad still hot, back bedroom hot,front bedroom flow pipe hot but rad is luke warm, entrance still cold, sitting room flow pipe hot but rad dosn't seem to be getting hot, kitchen flow pipe hot rad just off cold pump values 32w and 0.4m3/h. With both towel rails shut off the pump values are 22w and the m3/h gradually drops to 0.0m3/h . Both bedroom rads are warming up, entrance is still cold, sitting room and kitchen starting to warm up.I was wondering if there was a problem with the pump reason being I have to keep on reinstalling go remote to change the settings, also are the Alpha 3 and the Alpha2 exactly the same pump apart from how the Alpha 3 is adjusted and setup if so I was thinking of removing the head from the Alpha 3 and replacing it with the head from the Alpha 2 to see if that made any difference
 
It's amazing how the flow drops off with both T.rads shut, would wonder if any problem with system pressure...EV pipe blockage etc but as system was refilled using this then? You might just increase pressure by topping up to 1.5bar.
The pumps appear to be the same so probably OK to swap heads, but as you can easily isolate maybe easier to swap whole pump?
 
It's amazing how the flow drops off with both T.rads shut, would wonder if any problem with system pressure...EV pipe blockage etc but as system was refilled using this then? You might just increase pressure by topping up to 1.5bar.
The pumps appear to be the same so probably OK to swap heads, but as you can easily isolate maybe easier to swap whole pump?
what would be the max pressure I could use on this system/ easier for me to just unbolt 4 bolts and swap heads
 
The boiler PRV lifts at 3bar so wouldn't,t pressurised to move than 1.5/1.7 to avoid lifting it when system heats up. Changing pump heads only gives you a opportunity to inspect impellers for sludge build up.
 
The boiler PRV lifts at 3bar so wouldn't,t pressurised to move than 1.5/1.7 to avoid lifting it when system heats up. Changing pump heads only gives you a opportunity to inspect impellers for sludge build up.
Hi john the system used to heat up no bother with the old bathroom rad and the smaller sitting room rad so I have eliminated both of them by closing them off, if the problem was with those two items then the system should now heat up with no problems unless there is an airlock somewhere and the only way I would be able to say for definite would be to carry out flushing the system section by section, if no airlock was present then the only solution is the Alpha 3 is not doing what it is supposed to do, I can change the heads but I would not be able to say the Alpha 2 was in a working condition, but if the system heated up then it's proof the Alpha 3 is cattle trucked agreed?
 
Yes, go for that, should be a simple task, back flush from both sides when pump head removed but keep system topped up and to 1.5bar finally.
 
I removed the heads from both of the pumps and the size of the impellers are totally different, the Alpha 3 is only 38mm in dia where as the Alpha 2 is 63mm in dia so I am going to have to swap over the whole pumps
Hi John I changed the pumps over and put the Alpha 2 on it's highest setting, there was no difference which makes me think (as I have not done the flushing yet) there is a blockage in the pipe line, I put my thinking cap on and came up with this, the picture that is in the attachments of the towel rail plumbing, as the towel rails were off, the system was acting as before so I opened the small towel rail and it started to get hot in no time at all, so I concluded that the flow and return for that towel rail was ok, the same applies to the large towel rail, but when I turn the towel rails off the system goes back to where it was before so I am thinking the blockage could be where the return from the front bedroom meets the return to the boiler any ideas?
 
Hi John I changed the pumps over and put the Alpha 2 on it's highest setting, there was no difference which makes me think (as I have not done the flushing yet) there is a blockage in the pipe line, I put my thinking cap on and came up with this, the picture that is in the attachments of the towel rail plumbing, as the towel rails were off, the system was acting as before so I opened the small towel rail and it started to get hot in no time at all, so I concluded that the flow and return for that towel rail was ok, the same applies to the large towel rail, but when I turn the towel rails off the system goes back to where it was before so I am thinking the blockage could be where the return from the front bedroom meets the return to the boiler any ideas?
Hi John, well I cut out the "T" piece I thought might be the problem but it was ok , what was left now was an open return that was connected to that "T" so I connected a drain pipe to it, one end that was open that went to a towel rail I blanked that off, the other open end went to the boiler so I blanked that end off so I started to flush the system using the filler - expansion tank as the flow the water went through the boiler past the "Y" plan valve and into the flow pipe opened up each rad in turn and got a flow in was not very strong in fact I could stop it by putting a finger on the end of the return drain pipe, I flushed out each section in turn by opening and closing the return valves on each rad, got exactly the same flow through each section, I am going to try and put mains water pressure through the flow, by eliminating the expansion tank, boiler and "Y" plan valve and should get mains pressure back out of the return drain pipe if I do then it is as I said at the start the pumps that I have are not strong enough for my system or they are both knackered which means I need a stronger pump any ideas on these :- Britherm SL 25-80/180, Brithem super 25-120/180, Britherm Pro 2580/180, yes I know the port to port is 180 mm but that is easily overcome.
 
Sorry for late reply, didn't get any email notification(s) of your posts.
Will read the above in more detail later.

You have a sealed system so you will have the same pressure throughout the system and it will be at the EV pressure (with allowance for elevation) so if you were to attach a pressure gauge to any part of the system then you should get 1 to 1.5bar?? pressure, makes me wonder (again) where it joins the system exactly. Unless the system is 100% blocked in places then you should feel that pressure if you hold your finger over any point of opening, if there is a blockage then yes the flow will reduce to a trickle once you remove your finger.
When you were testing/flushing, how did you keep the EV pressure at 1/1.5bar?. also whether flushing with the EV or mains, ( not a bad idea), ensure the 3 port valve is, preferably latched in CH position but if not, latch it in mid position.

I would be very surprised if any one of those two pumps is knackered, if the impellers/pump ports are clear and you are getting the power associated with the mode settings and flows, and you were, then nothing wrong there IMO.

Where does the EV outlet join the system, is it before the pump?, you might remove it where it joins the system and ensure clear.
 
Sorry for late reply, didn't get any email notification(s) of your posts.
Will read the above in more detail later.

You have a sealed system so you will have the same pressure throughout the system and it will be at the EV pressure (with allowance for elevation) so if you were to attach a pressure gauge to any part of the system then you should get 1 to 1.5bar?? pressure, makes me wonder (again) where it joins the system exactly. Unless the system is 100% blocked in places then you should feel that pressure if you hold your finger over any point of opening, if there is a blockage then yes the flow will reduce to a trickle once you remove your finger.
When you were testing/flushing, how did you keep the EV pressure at 1/1.5bar?. also whether flushing with the EV or mains, ( not a bad idea), ensure the 3 port valve is, preferably latched in CH position but if not, latch it in mid position.

I would be very surprised if any one of those two pumps is knackered, if the impellers/pump ports are clear and you are getting the power associated with the mode settings and flows, and you were, then nothing wrong there IMO.

Where does the EV outlet join the system, is it before the pump?, you might remove it where it joins the system and ensure clear.
Hi john thanks for the reply, lets start from the beginning, I bought the Alpha 2 a few years ago when I found out there was something wrong with the basic Grundfos pump, after it was fitted it was working ok, then aprox 5 years ago we replaced the old boiler with the Worcester 15 Ri again everything was fine until last year when I put in the heated towel rails, I then thought that there was something wrong with the Alpha 2 pump so I bought the Alpha 3 but that did not solve the problem, as we have tested the system thoroughly and by eliminating the towel rails the system should have heated up the same as the towel rails but it did not, I think buying a new pump at this stage is not the answer because if the system was clear the Alpha 3 should have maintained 34w and 0.6m3/h at least but it did not it went back to 22w and 0.0m3/h and the system barely got warm, so I am thinking there is a partial blockage somewhere and I think, but I could be wrong, that it is in either the flow or return between the towel rails and the first real radiator which is the kitchen because if it was past the kitchen or for that matter before the front bedroom, the kitchen rad should have got hot and the entrance but they do not, the entrance does not heat up at all, so I am going to rod the flow and return and see what happens, if they are clear then I think it is a new pump
 
Can you just do up another line diagram just on that circuit including the rads, pump, 3 way valve & expansion vessel etc.
If the lines are clear then I would be almost 100% sure that a higher head pump will not sort the problem, we know (proved) that the Alpha 3 has a 6.4M head available and pumps 0.6m3/hr at this head, a 8M pump would increase the 0.6m3/hr flow to 0.67m3/hr and a 10M pump will increase the flow from 0.6m3/hr to 0.75m3/hr but neither can increase or get anything to flow where you have zero flow with a 6.4M pump head?.
 
Can you just do up another line diagram just on that circuit including the rads, pump, 3 way valve & expansion vessel etc.
If the lines are clear then I would be almost 100% sure that a higher head pump will not sort the problem, we know (proved) that the Alpha 3 has a 6.4M head available and pumps 0.6m3/hr at this head, a 8M pump would increase the 0.6m3/hr flow to 0.67m3/hr and a 10M pump will increase the flow from 0.6m3/hr to 0.75m3/hr but neither can increase or get anything to flow where you have zero flow with a 6.4M pump head?.
Hi john the line drawing is in the attachment and my way of thinking if there was a restriction in the flow after the "Y" plan valve any radiator that was prior to that restriction would heat up normally, if there was any restriction in the return line any radiator that was prior to that restriction would heat up normally, as the towel rails are both heating up and the rest of the system is just warming up or not getting warm the restriction if it was in the flow is between the towel rails and the kitchen, if it was in the return again the restriction would be between the towel rails and the kitchen, what do you think?
 

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That's great Ken, one picture is worth a thousand words.
From your post #80

All Rads ON 0.6m3/hr 34W
Large T.Rad Hot
Small T.rad Hot
Back B.room Hot
Front B.room L.warm
Entrance Cold
Sitting Room Cold
Kitchen Just Off Cold

Small T.rad Off, remaining Rads ON 0.4m3/hr 32W
Large T.Rad Hot
Small T.rad Off
Back B.room Hot
Front B.room L.warm
Entrance Cold
Sitting Room Cold
Kitchen Just Off Cold

Bothl T.rads Off, remaining Rads ON 0.0m3/hr 22W
Large T.Rad Off
Small T.rad Off
Back B.room warming up
Front B.room warming up
Entrance Cold
Sitting Room just about warming up
Kitchen Just about warming up

What strikes me straight away is the back bedroom, It stays Hot in the first two cases and is heating up with both T.rads off but with apparently no pump flow.
If its getting hot then that sort of proves that there is a flow through the main flow/return circuits? Can you try that Back B.room rad on only and see the pump values, if any?,

Are you sure that the isol valves on the 3 "cold" rads, Kitchen, Entrance and sitting room, are fully opened?

Flushing everywhere you can with the mains is about the most logical step now.

Your observations re restrictions make sense so running the back b.room on its own just might tell something.

1662463191786.jpeg
 
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That's great Ken, one picture is worth a thousand words.
From your post #80

All Rads ON 0.6m3/hr 34W
Large T.Rad Hot
Small T.rad Hot
Back B.room Hot
Front B.room L.warm
Entrance Cold
Sitting Room Cold
Kitchen Just Off Cold

Small T.rad Off, remaining Rads ON 0.4m3/hr 32W
Large T.Rad Hot
Small T.rad Off
Back B.room Hot
Front B.room L.warm
Entrance Cold
Sitting Room Cold
Kitchen Just Off Cold

Bothl T.rads Off, remaining Rads ON 0.0m3/hr 22W
Large T.Rad Off
Small T.rad Off
Back B.room warming up
Front B.room warming up
Entrance Cold
Sitting Room just about warming up
Kitchen Just about warming up

What strikes me straight away is the back bedroom, It stays Hot in the first two cases and is heating up with both T.rads off but with apparently no pump flow.
If its getting hot then that sort of proves that there is a flow through the main flow/return circuits? Can you try that Back B.room rad on only and see the pump values, if any?,

Are you sure that the isol valves on the 3 "cold" rads, Kitchen, Entrance and sitting room, are fully opened?

Flushing everywhere you can with the mains is about the most logical step now.

View attachment 77437
Hi john put mains pressure to the flow after disconnection from the "Y" plan valve thus eliminating pump, boiler, "Y"plan valve and domestic hot tank, both towel rails shut off from flow, only kitchen rad fully open did get flow but as the piping to that rad is 8mm bore got a reduced flow but i would have thought that if mains pressure was going through it the water would have squirted out but it did not could stop it with light finger pressure, so I opened the back bedroom so only kitchen and back bedroom fully open flow increased but not to what I would have expected could stop it with finger pressure, which makes me think that there is a restriction somewhere in the system, to my thinking as before between towel rails and kitchen whether it's in the flow or return needs investigation, I am going to try and rod the flow and return with welding rods joined together, see what happens.
 
You certainly shouldn't be able to plug any opening with your finger doesn't matter how restricted the pipe is as the pressure will build up regardless? assuming mains pressure.

Maybe prove main piping clear first by breaking the return at the boiler and flushing through, then measure into a bucket for 30 secs or so to get the LPM, by making a educated guess at the mains pressure then can see if flowrate is ok for x meters of 15mm piping?.
 
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You certainly shouldn't be able to plug any opening with your finger doesn't matter how restricted the pipe is as the pressure will build up regardless? assuming mains pressure.

Maybe prove main piping clear first by breaking the return at the boiler and flushing through, then measure into a bucket for 30 secs or so to get the LPM, by making a educated guess at the mains pressure then can see if flowrate is ok for x meters of 15mm piping?.
At this moment I think I have made some progress, as I said I was going to rod the pipework with 1/8 gas welding rods soldered together with a length of aprox 12-15 foot, I rodded the return which I had previously cut nothing going on there, I then cut the flow and the rod went in so far and I felt a bit of resistance so I pushed and fed the rod in further and used an in and out motion till it felt quite easy, then I connected the mains to the return opened up the furthest rad from the boiler connected a drain to the flow so that if there was anything in the system it would not flow round the system but out of the flow into the shower tray, you should have seen the amount of hard lumps of magnetite that came out, I am going to rod it again and see if any more comes out once it is clear I will reinstate the pipe work and try it, if all is clear or much improved I am thinking of getting it power flushed then fitting a magnaclean.
 
At this moment I think I have made some progress, as I said I was going to rod the pipework with 1/8 gas welding rods soldered together with a length of aprox 12-15 foot, I rodded the return which I had previously cut nothing going on there, I then cut the flow and the rod went in so far and I felt a bit of resistance so I pushed and fed the rod in further and used an in and out motion till it felt quite easy, then I connected the mains to the return opened up the furthest rad from the boiler connected a drain to the flow so that if there was anything in the system it would not flow round the system but out of the flow into the shower tray, you should have seen the amount of hard lumps of magnetite that came out, I am going to rod it again and see if any more comes out once it is clear I will reinstate the pipe work and try it, if all is clear or much improved I am thinking of getting it power flushed then fitting a magnaclean.
Hi John HURRAY sorted the rads are getting hot now just goes to show magnetite the root of all evils, rodded the flow for the second time and got a lot more out, I am going to get the system power flushed after we come back from our hols, then I am going to fit a magnaclean, obviously the heating will get better once I have balanced it, it still has the Alpha 2 pump in it, I will keep the Alpha 3 as a spare.
Thanks for all your help much appreciated
All the best Ken
 
Excellent news, I will have a few extra drops of Jamesons tonight not to mention a rake of Guinness.

Does the Alpha 2 display values as well?, W (watts) will do fine. If so, when you get a chance you might run it on CP2 which is 3M and post the values, or/and any values you have just now, that will give a very good indication of how clean the system is.

What exactly does a power wash achieve that you havn't already achieved, or how does it work??. you can flush out each rad individually in your own time and add inhibitor when all is done.
 

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