Combi boiler

carefullycautious

I have a thermostat on the wall and the boiler is only turned off from this to nought if we are not here.

I have set it to 18 degrees and the boiler has not stopped since I put it on earlier.

My room temperature gauge says it is 21 degrees so why does the boiler keep going and not cut off.

I am only asking as I am aware of the noise it makes, it seems to stop for a few seconds and then off it goes again. Is this how these boilers work. All I keep thinking is how much is this going to cost.

Forgive me if this is normal as it is the first type of boiler of this kind I have had the last one was really quiet.

pcgtron

Firstly you should never set the thermostat to 0 when you go away. Set it to about 100, that way your pipes won't freeze on you should the temperature drop below freezing. Also iit's not your room temperature that the boiler works on but the temp where the thermostat is positioned as this is the device that turns the heating on and off if it's set to come on.

I_have_spoken

My room temperature gauge says it is 21 degrees so why does the boiler keep going and not cut off.

Can you give us the make/model? If the thermostat is now always calling for heat, regardless of the actual temp., then the contact inside may have failed and got stuck closed so it's always energising the boiler.

it seems to stop for a few seconds and then off it goes again.

The boiler will have it's own thermostat where you set the CH water temp (or a maximum temp safety cut-out so it doesn't boil).

As the thermostat seems to be stuck, the boiler will fire until the water is at max. temp then shut off. Once the pump has circulated cooler water back from the radiators, the boiler will fire again. That's "short-cycling".

I have a thermostat on the wall and the boiler is only turned off from this to nought if we are not here

If you have to replace the thermostat, I'd take the opportunity to install a 5:2 programmable roomstat to give you far more control and lower running costs.

missesther

If it's any help, my combi boiler is pretty silent, I don't even know that it's on. What make do you have? Mine's Worcester Bosch.

I stayed at my parents whilst some work was being done on my house and they had an Ideal conventional boiler and it was so loud, it kept me up at night!

carefullycautious

Hi sorry to take so long to get back to you all.

It is a Glow.worm Ultracom CXI 30cxi condensing combination boiler.

carefullycautious

It has only recently been serviced. I will take a closer look at what the settings are on later.

cyclonebri1

Either you have set something wrong as per your latest post or the thermostat is either faulty or out of circuit.

The whole idea of a room/(whole system) thermo is that if this room goes over temp, the stat shuts down the lot, end of,

If it doesn't it's as above