Pilot light always on?

[mane]

This is what worries me. If the flame goes out because the gas supply is cut without my knowledge for example, then when the gas supply is restored I will know about it too late ....

Yes I understand but this is the point of the flame rectification and ignition sparking when no pilot light is detected. The pilot will re-light automatically if the ignition and pcb etc are working correctly

Yes, but that is fine if the boiler is on! If it is off then there is no ignition. There is just an open gas "tap" an no flame to consume it Note that currently the boiler is off and the pilot is on so there must be gas coming out.

At first I thought that the boiler is safe provided that the pilot flame remains alight. However there are all sorts of reasons why it can go off so I am starting to get worried. The only way to shut it really is to shut the gas at the meter and that means I will not be able to cook until someone comes and fixes the boiler.

What are the chances of a gas supply being cut?

 

[gas4you]

At first I thought that the boiler is safe provided that the pilot flame remains alight. However there are all sorts of reasons why it can go off so I am starting to get worried. The only way to shut it really is to shut the gas at the meter and that means I will not be able to cook until someone comes and fixes the boiler.

What are the chances of a gas supply being cut?[/quote]

All boilers have their own gas tap to enable them to be isolated seperatley. How about leaving it on and turning the boiler stat down to minimum. The ignition will be kept live then if the pilot goes out.

if in any doubt turn off gas and call out National Grid on 0800 111999 to make appliance safe. This is a free service.

 

[mane]

Hi all,

Just one final thought before this thread dies completely.

I am deeply concerned at the possibility of gas valves failling so soon/often.

This should not be the case. Despite this I have had 3 gas valves failures recently.

Currently I have the pilot flame valve stuck open. This is a potential explosion hazard if some reason the flame goes off (for example: gas supplier cutting off supply and turning it back on later. If the supply is back on and there is no demand for heat (the boiler if off) gas will just flow through the combustion products safety device waiting for an ignition source. If nothing else a heat demand at a later stage would do this!).

Assuming that both valves in the control valve are similar I have to assume that the main burner valve can possibly get stuck in the opened position. This means that I cannot turn off the boiler at all. If this happens when nobody is at home I don't even want to think about the consequences.

With this in mind I would like to open this discussion again into the potential causes for gas valve failures. These are not supposed to fail but somehow they are failing quite frequently in my central heating.

Many thanks
Mane

 

[namsag]

You have a gas valve that is passing gas when it should not be this is classed as immediately dangerous and gas supply to it should be turned off till a new valve is fitted. Get them back out

 

[mane]

Well....

Since I had to turn off the gas anyway, so I did it. Turned off the gas at the meter.

Then came back close to the boiler and watched the pilot flame die away slowly. Just before it was gone, I heard the magic click. At that point I thought that the valve might have closed after all.

Then I decided to turn the gas back on and run close to the boiler. I could not hear any gas flow or smell any gas. It appeared that the valve had closed as I suspected so I decided to try the boiler again.

I turned the control thermostat to 0 (to prevent the main burner lighting) and everything worked perfectly well.

I have turned the boiler on and off several times and all seems to work OK. The pilot flame is off when the boiler is off.

But still something remains unanswered. What was keeping the valve open or better, what was preventing the valve from closing? Could it be the actual gas pressure somehow? Could it be the thermocouple even without any mains powering the boiler? I am assuming the the thermocouple needs the PCB to monitor its small voltage. The solenoids need the 230V to operate.

Anyway, thank you all for your valuable comments so far.

Mane