Which is the more powerful pump?

[John.g]

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?.

 

[John.g]

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.

 

[rcpilot]

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.

 

[John.g]

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)

 

[rcpilot]

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

 

[John.g]

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?

 

[rcpilot]

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

 

[John.g]

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.

 

[rcpilot]

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?

 

[John.g]

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.

 

[rcpilot]

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.

will let you know how I get on

 

[rcpilot]

will let you know how I get on

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

 

[rcpilot]

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?

 

[Ben-gee]

Investigate that area of pipework with a magnet, if it’s attracted then chances are it’s full of steel based sludge.

 

[rcpilot]

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.