Which is the more powerful pump?

[John.g]

Doesn't seem possible, can you change to constant pressure mode CP3 which is a constant 4.5M, if not pumping in this mode then the power will read only 15W.

I did come across here sometime where a pump was displaying all the above symptoms but when the head was removed it was full of soft sludge with the impeller vanes choked, vanes can be cleaned with a tie wrap.

If its still not pumping on CP3, I would be inclined to isolate the pump and remove its head (2 or 4 stud bolts) complete with impeller and inspect it, then flush pump body ports alernatively tfrom he inlet and outlet valves, you will have to top up the boiler afterwards.

OR, if you still have the Alpha 2, simply install that and see will it pump, why did you replace it with the Alpha 3 as it has exactly the same performance but not the same amount of bells and whistles
If this pump was installed originally then you can look at this first for any signs of sludge inside, etc.

 

[rcpilot]

Have you still got the Alpha 2 pump?

yes I have, another thing could my problems be associated with the outlet valve, why I say that is because the pump has the common connections on it but I have a gate valve just above it and I have been using that to close off the outlet and I have had problems with that type of gate valve before where the brass gate dose not fully open or fully close but sticks in one position.

 

[rcpilot]

Doesn't seem possible, can you change to constant pressure mode CP3 which is a constant 4.5M, if not pumping in this mode then the power will read only 15W.

I did come across here sometime where a pump was displaying all the above symptoms but when the head was removed it was full of soft sludge with the impeller vanes choked, vanes can be cleaned with a tie wrap.

If its still not pumping on CP3, I would be inclined to isolate the pump and remove its head (2 or 4 stud bolts) complete with impeller and inspect it, then flush pump body ports alernatively tfrom he inlet and outlet valves, you will have to top up the boiler afterwards.

OR, if you still have the Alpha 2, simply install that and see will it pump, why did you replace it with the Alpha 3 as it has exactly the same performance but not the same amount of bells and whistles
If this pump was installed originally then you can look at this first for any signs of sludge inside, etc.

Do you think that if I flushed out the whole system with a good cleaner it might do the trick?

 

[rcpilot]

Doesn't seem possible, can you change to constant pressure mode CP3 which is a constant 4.5M, if not pumping in this mode then the power will read only 15W.

I did come across here sometime where a pump was displaying all the above symptoms but when the head was removed it was full of soft sludge with the impeller vanes choked, vanes can be cleaned with a tie wrap.

If its still not pumping on CP3, I would be inclined to isolate the pump and remove its head (2 or 4 stud bolts) complete with impeller and inspect it, then flush pump body ports alernatively tfrom he inlet and outlet valves, you will have to top up the boiler afterwards.

OR, if you still have the Alpha 2, simply install that and see will it pump, why did you replace it with the Alpha 3 as it has exactly the same performance but not the same amount of bells and whistles
If this pump was installed originally then you can look at this first for any signs of sludge inside, etc.

i did notice you mentioned CP3, the pump was set in constant curve, so I reset it to CP3 closed the valve and the pump stopped, reopened it and the pump reset itself to constant curve, i have been using my wifes new phone but it keeps losing the connection with the pump and is very hard to reconnect

 

[John.g]

yes I have, another thing could my problems be associated with the outlet valve, why I say that is because the pump has the common connections on it but I have a gate valve just above it and I have been using that to close off the outlet and I have had problems with that type of gate valve before where the brass gate dose not fully open or fully close but sticks in one position.

Yes, a prime suspect, its quite possibly closed now so if the threads arn,t stripped you should get 3 to 5 full turns anticlockwise from it , there's always a 1/2 to 3/4 of free play before they start to open or close.

Do you think that if I flushed out the whole system with a good cleaner it might do the trick?

Only as a very last resort IMO, get the pump working and we can see then if required.

If you do get it opened then leave it as Don,t require any more closed valve readings

 

[rcpilot]

Yes, a prime suspect, its quite possibly closed now so if the threads arn,t stripped you should get 3 to 5 full turns anticlockwise from it , there's always a 1/2 to 3/4 of free play before they start to open or close.


Only as a very last resort IMO, get the pump working and we can see then if required.

If you do get it opened then leave it as Don,t require any more closed valve readings

Ok John I will strip the Alpha3 out check the gate valve, if it is ok I will put the Alpha 2 back in to see if that makes any difference, will get back to you when it's done could be a few days, one thing I forgot to tell you is I suffer from a back problem, when I was working as a service engineer for a firm that serviced and repaired lifts,hoists cranes etc I fell off an overhead crane over in Carlisle many years ago and I back pain when i do too much

 

[John.g]

Did you manage to open it, remove handwheel and use a adjustable spanner as a lever.

Maybe just renew the gate valve and take from there, you can always check pumps later as you can isolate them?

 

[rcpilot]

Did you manage to open it, remove handwheel and use a adjustable spanner as a lever.

Maybe just renew the gate valve and take from there, you can always check pumps later as you can isolate them?

Hi john well striped the Alpha 3 out and guess what, both valves were barely open so that was the restriction to flow, I renewed some of the pipe work to one of the radiators because it had a service valve on it and it was leaking and I am now cleaning up after the work, if everything is hunky dory with the system what is the best setting for the Alpha 3 and I might try to balance it with the go balance app.
Ken

 

[John.g]

That's good news Ken, I would set it to CC3 to start with, if you have to close all the rad valves individually (no u/staors/d/stairs zoning), then just run it as is, ie, if d/stairs only opened up now just start the pump and post the numbers, you can then open up the u/stairs and run both systems together on CC3 and have a look at those numbers.
Don't know what the total rad(s) output is but assuming 20kw max then the flowrate required will be 20LPM (1.2M3/hr) at a rad dT of 14/15C/kw which would result in a pump head of 4.7M in CC3 mode, see what you come up with anyway and you can decide on balancing, if any, is required later.

My system, 12 rads, 20kw, no balancing, works fine at a 3.5M head.

 

[rcpilot]

That's good news Ken, I would set it to CC3 to start with, if you have to close all the rad valves individually (no u/staors/d/stairs zoning), then just run it as is, ie, if d/stairs only opened up now just start the pump and post the numbers, you can then open up the u/stairs and run both systems together on CC3 and have a look at those numbers.
Don't know what the total rad(s) output is but assuming 20kw max then the flowrate required will be 20LPM (1.2M3/hr) at a rad dT of 14/15C/kw which would result in a pump head of 4.7M in CC3 mode, see what you come up with anyway and you can decide on balancing, if any, is required later.

My system, 12 rads, 20kw, no balancing, works fine at a 3.5M head.

I have bled all the rads but left the kitchen one out of it for the time being, the bathroom towel rails are getting mad hot and the sitting room is starting to heat up, nothing yet in the bedrooms but I suppose balancing will bring them up

 

[John.g]

With CC3?
What pump values are you getting?

 

[John.g]

You said in post #1 that the upstairs rads were heating but not downstairs?,
If you have a Y system with a mid position valve then just carry out the basic check that the pump arrow is pointing towards it, also ensure that system is pressurized to 1.3/1.5 bar.
Can you also take pump values with DHW heating only on, then with (eventually) DHW+d/Stairs+U/stairs.

 

[rcpilot]

You said in post #1 that the upstairs rads were heating but not downstairs?,
If you have a Y system with a mid position valve then just carry out the basic check that the pump arrow is pointing towards it, also ensure that system is pressurized to 1.3/1.5 bar.
Can you also take pump values with DHW heating only on, then with (eventually) DHW+d/Stairs+U/stairs.

Hi John, this flaming thing has got me demented, when I put everything back together, filled the system, bled the radiators, then started it up it was showing 24 watts on the pump and I think 0.6m3/h and the towel rads were getting mad hot the big rad downstairs was getting hot, both bedrooms were cold obviously because the lockshields were closed, the entrance rad was still cold, so I turned it off. Today I turned it back on and got the same results, so I started to manually balance the towel rails got them somewhere near the 12 deg difference checked the pump and the wattage had gone down to 15 and the m3/h was showing 0.0, hair now all over the floor.

 

[rcpilot]

Hi John, this flaming thing has got me demented, when I put everything back together, filled the system, bled the radiators, then started it up it was showing 24 watts on the pump and I think 0.6m3/h and the towel rads were getting mad hot the big rad downstairs was getting hot, both bedrooms were cold obviously because the lockshields were closed, the entrance rad was still cold, so I turned it off. Today I turned it back on and got the same results, so I started to manually balance the towel rails got them somewhere near the 12 deg difference checked the pump and the wattage had gone down to 15 and the m3/h was showing 0.0, hair now all over the floor.

Hi John decided to check the pump with the "go remote app" that pump has got a mind of it's own it reset itself from CC to CP so I reset it to CC and operating @ max it went back to showing 24 watts but the flow rate remained @ 0.0m3/h

 

[John.g]

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.

 

[rcpilot]

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

 

[rcpilot]

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

 

[rcpilot]

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?

 

[John.g]

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.

 

[John.g]

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.

 

[rcpilot]

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.

ok will do

 

[rcpilot]

ok will do

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?

 

[rcpilot]

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

 

[rcpilot]

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!

 

[John.g]

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.

 

[rcpilot]

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

 

[rcpilot]

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

 

[John.g]

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?.

 

[rcpilot]

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.

 

[rcpilot]

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.

 

[John.g]

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

 

[rcpilot]

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

 

[John.g]

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.

 

[John.g]

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.

 

[rcpilot]

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,