Poor heating after changing radiator (Ed.)

[Alec_t]

Perhaps flow throught the primary heat exchanger in the boiler is now reduced by gunge dislodged when the rad was removed/replaced?

 

[Harry Bloomfield]

Would that not mean we would have really hot water and the radiators would be cooler? Whereas we have problems with both heating and hot water. Trying to riddle this through and feeling a bit stumped at the moment. Really appreciate your ongoing input!

No, once the cylinder got to temperature, its valve would close, and all of the boilers heat would then go to CH. As Alec suggests above, perhaps your heat exchanger in the boiler, has been choked up by debris, when the rad was changed? What condition is the water in, do you have a magnetic filter fitted on the return to the boiler?

 

[Stuckinarut]

Rather than re-read responses, have you tried bleeding the air vent on the pipe before the motorised valve in case of just an airlock?

 

[Carly900]

No, once the cylinder got to temperature, its valve would close, and all of the boilers heat would then go to CH. As Alec suggests above, perhaps your heat exchanger in the boiler, has been choked up by debris, when the rad was changed? What condition is the water in, do you have a magnetic filter fitted on the return to the boiler?

Perhaps flow throught the primary heat exchanger in the boiler is now reduced by gunge dislodged when the rad was removed/replaced?

I’ve been wondering if changing the radiator might have dislodged some sludge and clogged a pipe somewhere. All my pipework to the boiler is squeezed behind a set of drawers below the boiler cupboard but as far as I can see there’s nothing that looks like a magnetic filter on any of the pipework. I’ve already booked someone to come out to service the boiler but they’re not coming until 19th. If there’s anything we can do to test the blockage theory in the meantime please do let me know!

 

[Carly900]

Rather than re-read responses, have you tried bleeding the air vent on the pipe before the motorised valve in case of just an airlock?

We’ve bled the radiators but no vents on any pipes. We’ve been a bit reluctant to do much with the pipework around the hot water tank / underfloor heating manifolds in case we muck anything up (complete novices but off the back of all this I’ll be moonlighting as a plumber fairly soon!) will take a look around the diverter valve… what sort of thing should we be looking for to bleed?

 

[Stuckinarut]

what sort of thing should we be looking for to bleed?

Using a cloth, towel or similar, This (circled yellow) and any other air vents should be turned counter clockwise to open and should expel air, if you get water then there’s no air trapped. Turn clockwise again to close.

 

[Carly900]

Rather than re-read responses, have you tried bleeding the air vent on the pipe before the motorised valve in case of just an airlock?

Ok, identified the automatic bleed valve on the pipe near the diverter valve, unscrewed it, some water came out, screwed it back on. I assume this counts as bleeding it? Will see if that makes any difference.

 

[Carly900]

Using a cloth, towel or similar, This (circled yellow) and any other air vents should be turned counter clockwise to open and should expel air, if you get water then there’s no air trapped. Turn clockwise again to close.

Didn’t see your most recent reply, yes that’s the valve we unscrewed, so seems like that’s all fine! Thank you

 

[Harry Bloomfield]

We’ve bled the radiators but no vents on any pipes. We’ve been a bit reluctant to do much with the pipework around the hot water tank / underfloor heating manifolds in case we muck anything up (complete novices but off the back of all this I’ll be moonlighting as a plumber fairly soon!) will take a look around the diverter valve… what sort of thing should we be looking for to bleed?

When you are bleeding radiators, what colour is the water which comes out? It should be discoloured much, almost clear.

 

[Carly900]

Just to (hopefully) round out this saga - I think we finally got the problem fixed.

We managed to get the plumber over who originally fitted the system for our builders. He was only here about half an hour and identified that one of the valves on the boiler was closed. Not sure how that happened, possibly my husband accidentally moved it when he was increasing the water pressure after changing the radiator. Anyway, plumber said that with that valve being closed the water wasn’t getting away from the boiler quickly enough. He reckons that’s caused all the issues.

Thanks so much to everyone for all their help! Really really appreciate it!