Wicks 40 (Horstman?) Boiler failure

[Vass]

My aging Wicks 40 Boiler has stopped working It started rumbling, then it cut out the flame I think its overheating, so now when hot, the pilot will not light And when I di get it lit, and start the boiler after its warmed up the boiler cuts the flame (saftey feature I guess)

Am I right in thinking the probe thingy stick in the side on a coiled copper looking wire/pipe has failed and needs replacing? is this called the thermostat or thermocouple?

Can anyone tell me the real make of my boiler? its says Wicks 40 and thats it. Just a boiler stick on the wall, flames below a tank with exhaust tot he outside and a large square plate out side on the wall. OR where can I look for model number info on the boiler?

Plus, anyone know a place I can get the part today? Portsmouth area UK Thanks in advance

[Andy Hall]

The thermocouple to which you refer is a flame failure device designed to turn off the gas in the event of the pilot failing to light or remain alight.

If the boiler is overheating, the reason for that needs to be investigated.

The thermostat turns off the main burner when the water is hot enough, but shouldn't turn off the pilot.

It would be safer (and legal) to call in a heating engineer to fix it.

[Vass]

ok so the probe is connected to the thermostat so what is causing the boiler to overheat if the thermostat is working correctly? this makes no sense

[Andy Hall]

It can make a great deal of sense.

For example:

- The pump may be broken or on its way out

- There could be a partial blockage in the heat exchanger or elsewhere in the system.

If the temperature rises quickly enough, the overheat sensing can trip.

However - back to the original point of it cutting off the pilot.

Either way, if the OP is not sure about what he is doing, he should seek the help of a professional.

The problem may only be the thermostat, but other things should be checked as well.

[legin]

Sound advice. The boiler may have a thermocouple which is linked to the overheat stat, hence when it overheats it cuts the pilot. The overheat stat may have gone sensitive but is an important safety device. Are there Trv's on all of the radiators so when the rooms are warm there is no where for the heat to go? Is the pump failing and cannot get the heat away from the boiler. A temporaray fix may be to turn the boiler stat down so that the water temp is reduced and hopefully will not trip the overheat stat. It may just keep you going until you can get an engineer in.

Legin

[Vass]

thanks for the advice The rest of the system, pump, valve, tank etc are all new so its the boiler IMLO The massive rumble when the boiler is hot, leads me to think its boiling the water but, llike you say, if the pumps working, the water should'nt stay in the boiler long enough for it to behave like that No TVR's on the rads, but its been flushed 3 times this year so blockage maybe not - no black sludge or anything Thermostat ordered for next day delivery and Gas engineer coming tomorrow when I ring him to let him know the parts arrived. I might try lowering the dial on the thermostat to see if it behaves today as suggested. thanks again

[Vass]

(Halsted not horstman)

[Andrew Gabriel]

I thought he was referring to a thermometer phile.

[Andy Hall]

Yes, you're right, my mistake.

However, it looks like Geoff's explained it.