Oh dear - boiler looks like it's had it

[Oneeyedvic]

We have an oil fired boiler which is around 25-30 years old. It was serviced earlier this year and was working okay. We live in a fairly big house and so 3 weeks ago, we had a load of TRVs fitted to the radiators so that we could actually turn off supply to a couple of rooms which don't get used much.

Everything was running fine until yesterday. Now some of the radiators are not getting hot at all despite the fact that they were last week.

Question is - is this more likely to be the pump or will our boiler need replacing?

[stanleyman]

Unlikely to be the boiler unless the burner has locked out. Could be pump, air or low water but have you thought that it might be the TRV's have shut down? Adjust to get the right room temperature.

[stanleyman]

As from next year new oil boilers have to be high efficiency condensing boilers. You would save a lot on fuel by changing it. Your boiler probably 65% efficient, new condensing boiler 95% efficient.

[Oneeyedvic]

Not sure what you mean by TRVs shut down - these were all working fine last week, and temperature was fine in each room.

[stanleyman]

TRV's turn off the rad completely when the set temperature is reached so the rad will go cold until the room temperature drops again and the TRV opens. The room may simply be warm enough for the TRV setting. That's assuming the heating is on and any roomstat is calling for heat.

[Hard@it]

As stanleyman says t/vs sound as if reaching temp, take heads off rads. not wking. and if they heat up then all ok. If not then they are on wrong connection and should be changed to other end of Rad., or if heads are vertical then they are sensing heat from pipework, all heads should be horizontal and away from any direct heat source. I take it you have not changed pump?

[gastwo]

Wouldnt hurt to get your radiators 'back-flushed', either. Most reputable plumbers offer this service - basically take the rads' out of service one by one and back-flush them with a fluid to remove build up of scale and detritus. They then recharge the complete system with fresh anti-corrosion fluid. Costs �300 - �400 for a 3 bed house, but the result is well worth it.