Female Central Heating

[chadspad]

Hi, my c/h is currently misbehaving & hope u can help. For example, with the c/h & h/w set to run continuously & the room stat set at 30 deg, the boiler fires up & eventually shuts off but won't come back on again without
switching the boiler off & on (repeatedly). If the c/h hasn't come on overnight then there's no hot water either.
Duff room stat was suggested so I replaced that with no joy
Had plumber round, he said diverter valve was stiff so I replaced head ass'y. he also thought the cold water feed could be partially blocked with crap (don't know how that got in there) causing the boiler stat to override, so I cleared that out & still no joy
So it's down to you guys to pick your brains
The love of my life reminds me that problem coincided (but not proven as guilty) with a rad valve splitting & dumping black gloop over lounge floor.
Cheers for your help in advance

 

[sifu]

What boiler make/model is it? If the diverter valve body is stiff then replacing the head won't cure this. Sometimes turning the body manually will loosen it. If it's a Danfoss/Randall or Potterton then turning the spindle 360 degs several times will free it but this can also cause the spindle to weep. If you have a fanned flue boiler then sometimes the air pressure switch can stick in the n/c position. The boiler won't fire unless the APS is in the n/o position. When you have the problem does the pump run or not and is their any movement from the diverter valve, particularly a clicking sound?

Paul

 

[chadspad]

boiler is Stelrad Ideal Classic NF40.
He meant the spindle was stiff to turn & that the head would need replacing.
I'll have to check out the rest & get back

many thx for your input