NEW HOT WATER CYLINDER - NOW CENTRAL HEATING NOT RIGHT

[JJcasper]

I have a nightmare of an old heating system, finally got the rads balanced as best as I could then old cyclinder leaked right through living room ceiling and had to get an emerg plumber in to replace it. He did it, finishing 1pm-ish today. It's now 6.55pm and there's very little heat going through rads, feed pipes feel hot (as hot as they get in this house) but the rads are tepid at most. stacks of very hot water in taps from the boiler, and I know its heating the central heating water, but it's just not moving along, even turned the pump up to max. any suggestions - it's blooming cold!

 

[gigz]

Sounds like sludge or air, or you're pump could be knackered

 

[JJcasper]

can hear the difference when pump turned up or down, so hoped that means it's working. It was yesterday. system was all fine until the new cylinder. bled radiators - no air. perhaps it's time to have a bosh at flushing out the rads?!

 

[kevplumb]

bleed the pump (see faq)

ie undo the screw in the centre

 

[JJcasper]

done that thanks, time will tell................ fingers crossed. ta

 

[arfurrrr]

what about the bypass valve or the valve which controls the flow rate of hot water in to the cylinder coil , if thats fully open the pump will pump the easiest route .

is you hot water heating up ok ?

 

[JJcasper]

yes, hot water is great. sorry bypass valve is a new one on me - can you explain please? thanks

 

[arfurrrr]

There should be a valve on the inlet or out let to your DHW cylinder where the central heating pipes enter if this is fully open the then pump will pump all the heated water through that until the cylinder stat is statisfied then the DHW diverter valve will close . before the DV valve the should/could be a section of pipe which bypasses the cylinder and connects onto the return pipe to the boiler. it has a valve on it . If this valve is fully open then the same will happen .

Its purpose is to allow the circulation of water should the boiler be running and the pump have no where to circulate the water .

 

[JJcasper]

thanks - will check it out

 

[kevplumb]

I have a nightmare of an old heating system,

me thinks gravity h/w arf