Housewarmer economy pilot light not working

[camerart]

Hi,
I turned my Housewarmer Economy 45 off for a clean, and when I tried to re-light the pilot light it won't stay lit.
Here is a diagram showing the pilot start buttons:
The procedure for lighting is: Push the Gas valve operating button-press the Ignition button and hold for 1/2 minute. The pilot lights up ok, but goes off when the Gas valve button is released.

The gas valve button, also twists clockwise. Why is this? Does it need to be twisted when holding?

Any answers please?
The boiler was installed 1986, so there's plenty of life in it yet

Camerart.

 

[terryplumb]

Try holding the gas valve button in for longer after the pilot is alight ,gives the thermocouple a bit longer to heat up.then release it slowly.

 

[camerart]

Try holding the gas valve button in for longer after the pilot is alight ,gives the thermocouple a bit longer to heat up.then release it slowly.

Hi T,
5 Minutes, still no good!

Can you clarify, about the Gas valve button. Are there any connections inside it, or is it just gas channels? What difference does twisting it make?
C.

 

[terryplumb]

Not too familiar with mysons range of housewarmers ,but the principle is the same on pilot ignition . some you turn the thermostat to off. Then press and hold the gas valve button ,this manually opens it allowing gas to flow to the pilot .pressing then the igniter creates the sparks which then gives you the pilot flame. This flame heats the thermo couple ,which then generates a small electric charge ,sufficient to keep the gas valve open. After 30 to 40 seconds. You then release the gas button. If the pilot goes out then the thermocouple is suspect.is it possible you may have disturbed it when cleaning ?? One end has to be in proximity of the flame and the other end is affixed to the gas valve. After a failed attempt to light the pilot ,its usual not to try again for three or four minutes. As the pilot is actually lighting then the gas valve button that you press is doing what its supposed to, unless the pilot flame is extremely weak ( small / low ) compared to what you have seen historically.

 

[camerart]

Hi T,
You description sounds correct.

I'm still puzzled by the push or twist of the gas valve. It may be possible the twist is for venting the gas away before trying to spark again?

I'm suspecting the thermocouple also. It could have gone because of the shock of getting cold for a while.

If it is the thermocouple: Is it electrical or filled with a gas?

If it's electrical, I can test it. Do you know what the readings could be?
C.

 

[ReganAndCarter]

If you search 'how to test thermocouple' on Youtube, you will find plenty of videos on how to test one with a multi meter.

 

[camerart]

If you search 'how to test thermocouple' on Youtube, you will find plenty of videos on how to test one with a multi meter.

Hi R,
I've been looking at some, thanks.
C

 

[camerart]

Hi,
First I noticed that the pilot light flame wasn't directly aiming at the thermocouple, because there is a tube over the pilot light that had corroded. Bought a new one, but didn't fix it.
Next I tried the current from the thermocouple, as normal, 10mV with an added flame 30mV, so I think this is ok.
Next I tried the resistance in the Gas valve, nothing, so now I suspect the Gas valve.
C.

 

[Wildcat1961]

If the pilot goes out then the thermocouple is suspect

Or possibly TMV/pilot flame/TC connection...

 

[camerart]

Or possibly TMV/pilot flame/TC connection...

Hi W,
Do you mean the thermocouple to gas valve connector?
I took out the thermocouple relay, and there's no continuity, between the contacts.
C

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