Pilot Light Problem

terrymats

Hi guys,

I've got an old boiler in my house which was fitted by the previous owners. A new problem has popped up recently.

My baby girl accidentally turned off the electric supply to the boiler. When i turned on the supply and tried to light the pilot, it would not stay after holding the white button for 20 seconds. It remained stable after 10 odd attempts; and we had heating. But the next morning, my house was damn cold and I realised that the light went off at night.

I've been doing this for the past 4 days now and the house is sometimes cosy, but mostly chilly. I don't know what to do. I did bleed all raditors, made sure all had sufficient water and there's only one fuse in the circuit which is working fine. There doesn't seem to be a gas leak (no smell atleast). Just noticed that one of the radiators had leaked a bit on the carpet. Maybe 1/2 a glass of wine (small glass). But then, nothing else has happened in these four days except this odd problem.

Another problem is, there are three radiators on the first floor(top) of my house. They all seem to lose water over time and I need to refill them time & time again. What would be the problem here and is it realted to the first one?

Would appreciate all help in this situation.

Thanks
Terry

PS: What is the frequency suggested to have a boiler serviced? I think mine hasn't had one since a fair amount of time.

Cardew

terrymats wrote:

Hi guys,

I've got an old boiler in my house which was fitted by the previous owners. A new problem has popped up recently.

My baby girl accidentally turned off the electric supply to the boiler. When i turned on the supply and tried to light the pilot, it would not stay after holding the white button for 20 seconds. It remained stable after 10 odd attempts; and we had heating. But the next morning, my house was damn cold and I realised that the light went off at night.

I've been doing this for the past 4 days now and the house is sometimes cosy, but mostly chilly. I don't know what to do. I did bleed all raditors, made sure all had sufficient water and there's only one fuse in the circuit which is working fine. There doesn't seem to be a gas leak (no smell atleast). Just noticed that one of the radiators had leaked a bit on the carpet. Maybe 1/2 a glass of wine (small glass). But then, nothing else has happened in these four days except this odd problem.

Another problem is, there are three radiators on the first floor(top) of my house. They all seem to lose water over time and I need to refill them time & time again. What would be the problem here and is it realted to the first one?

Would appreciate all help in this situation.

Thanks
Terry

PS: What is the frequency suggested to have a boiler serviced? I think mine hasn't had one since a fair amount of time.

Turning off the electricity should not extinguish the pilot light. It sounds like you have a problem with the thermocouple - although I am no expert. The quote below explains a thermocouple.

Many gas-fed heating appliances like ovens and water heaters make use of a pilot light to ignite the main gas burner as required. If the pilot light becomes extinguished for any reason, there is the potential for uncombusted gas to be released into the surrounding area, thereby creating both risk of fire and a health hazard. To prevent such a danger, some appliances use a thermocouple to sense when the pilot light is burning. Specifically, the tip of a themocouple is placed in the pilot flame. This thermocouple electrically operates the gas supply valve responsible for feeding the pilot. So long as the pilot flame remains lit, the thermocouple remains hot and holds the pilot gas valve open. If the pilot light goes out, the temperature will fall along with a corresponding drop in electricity, removing power from the valve. Unpowered, the valve will then automatically shut off the gas, halting this unsafe condition.

Obviously a sealed CH system should not lose lots of water and it doesn't sound as if the small leak would account for the loss you are experiencing.

It is recommended that gas boilers are checked for safety annually, although this is not mandatory unless the property is rented.

james123

had just the same problem,although mine was due to the electricity running out!! Our CH wouldnt work, and after taking the pump apart and talking to FIL for about an hour realised it was that the power cut had caused the boiler to "trip". I had to remove the bottom cover of the boiler and on the underside there was a tiny red button, i had to push it really hard, but this reset the boiler and now all is fine.

terrymats

Thanks Cardew,

I'm not really an expert on such issues, but being from a technical background ( i did mention the thermocouple you are talking about). As i don't use match sticks, I usually lit the pilot using a long fold of paper. Probably the ashes of the burnt paper were deposited on the thermocouple? I tried to clean it off before posting here. The boiler is working at the moment.

Also noticed that when I touched the thermocouple, the pilot sometimes went off. Realising that it was not getting proper heat (i noticed that the flame was a bit away), i tapped the thermocouple a few times (which looked like a curled up coil coming outside the pilot) which probably heated it properly and the boiler did light up today after a long struggle.

So it seems like the thermocouple is a problem and may need replacing. However, i'm still worried about the top floor radiators losing their water. What can be done about this? Has it got anything to do with the hot water that runs in the bath and the sink?

Besides, where is the best place to get this thermocouple and is it easy to replace? If yes, what about be the cost of it?

Thanks

caveat_emptor

There are a number of online boiler spares suppliers, try Googling.
Some air will get trapped in the highest point in the system but shouldn't need bleeding very often. How often do your rads need bleeding?
Hot water at taps is isolated from heating water either in hot-water cylinder if system is vented or at boiler if system is sealed.

terrymats

I need to topup my first floor radiators literally every fortnight. Any ideas?

ariba10

terrymats wrote:

Thanks Cardew,

I'm not really an expert on such issues, but being from a technical background ( i did mention the thermocouple you are talking about). As i don't use match sticks, I usually lit the pilot using a long fold of paper. Probably the ashes of the burnt paper were deposited on the thermocouple? I tried to clean it off before posting here. The boiler is working at the moment.

Also noticed that when I touched the thermocouple, the pilot sometimes went off. Realising that it was not getting proper heat (i noticed that the flame was a bit away), i tapped the thermocouple a few times (which looked like a curled up coil coming outside the pilot) which probably heated it properly and the boiler did light up today after a long struggle.

So it seems like the thermocouple is a problem and may need replacing. However, i'm still worried about the top floor radiators losing their water. What can be done about this? Has it got anything to do with the hot water that runs in the bath and the sink?

Besides, where is the best place to get this thermocouple and is it easy to replace? If yes, what about be the cost of it?

Thanks

One end of the thermo couple is in the flame the other is held in the valve with a small nut. Check the see that it is reasonably tight, it needs to make good contact.

terrymats

ariba10 wrote:

One end of the thermo couple is in the flame the other is held in the valve with a small nut. Check the see that it is reasonably tight, it needs to make good contact.

It's tight. I checked it when I thought that the thermocouple was not making good contact with the flame.

jennifernil

Is this a combi boiler? If it is losing water them you must have a little leak somewhere.You will need to add water manually. If it's a regular boiler you should have a little header tank in the loft with a ball valve so it tops up automatically, but you still must have a leak. It may be under the floor , so you would not see it .

"New" water entering the system will contain some air, so if you have a leak and you/it keeps topping up you will need to vent the radiators more often. As the air naturally rises most of it will end up in the upstairs radiators, making them colder.
Have you checked that the drain tap for the system is properly turned off?

terrymats

I'm not sure what you mean by a combi boiler. Take it that it provides heating for the radiators + the bath & sink. I believe this is the one I have. Besides, it may be noted that I never used the top floor rads for 1 year. In such event, the downstairs rads worked perfectly fine and did not need bleeding. Also, could you tell me where I can find the drain tap? Is it on the boiler somewhere?

jennifernil

A combi boiler is one which heats the hot water ( for the bath etc) on demand. There is no hot water cylinder. It is then a pressurised system which you need to keep at a certain minimum pressure.

Do you have thermostatic valves on the radiators? If so and they were not used for a long time they may be stuck, or the unused radiators may be full of sludge.

The drain valve should be at the lowest point on the system, normally you would have either a little drain-tap coming out through the wall of the house below ground floor level, or just a bit of pipe coming out and a stop tap maybe next to the boiler if it is a combi.