After thermocouple change pilot light won't stay lit

[benji]

Hi,
I have a 14 year old glowworm economy 100 gas combi boiler. Four days ago I tried to light the boiler the usual way after adding gas to my pay as you go gas meter. This means pressing the piezo button to light the pilot and keep it pressed in for 15 seconds until the pilot light stays lit. On this occasion it didn't. After sixteen attempts I checked on the web to check why this occurs. I didn't have the money for a plumber and it hasn't been serviced for quite some years now. I found out the the thermocouple is the usual reason for the pilot light not staying lit. So I went to B&Q and got a univeral thermocouple(30"), to replace the original (18"). I managed to replace it without too much problems and careful not to upset any settings in the boiler. Well I thought this did the trick but the pilot light will still not stay lit. What else can I do? I need to find an answer quick as my kids get colds quickly.... and ITS COLD!!
Recent snow storm in the Croydon area didnt help!

 

[kevplumb]

is the pilot frame envoloping the thermocouple tip and is it blue

 

[benji]

Hi Kev,

Yes the flame is blue and I positioned the thermocouple tip so that it is enveloped by the flame. I pressed in the piezo button for a maximum of two minutes thinking that this would heat the thermocouple tip sufficiently to send a heat signal or electrical charge or whetever to a sensor. Still no joy!

 

[kevplumb]

are there any wires where the thermocouple connects to the gas valve

 

[benji]

Yes - I think,

The thermocouple connects to a part that connects to an electrical sensor and also a pilot chamber where there is an adjuster in the shape of a screw head with a flat head indentation(not philips - cross head). I think this is the gas valve - is it?

 

[kevplumb]

1 are you sure its fitted correctly
2can you use a meter
3 have you got the instructions

 

[benji]

1 are you sure its fitted correctly
2can you use a meter
3 have you got the instructions

Hi,

1 - I am sure I fitted it correctly. i checked how the original one was fitted and the new one had a copper sleeve so the the thermocouple tip could fit in to the housing.

2 - I do not hav a meter

3. I have just found the servicing instructions for the boiler. I checked where the gas valve assembly is and yes I can confirm that there are wires connected to it.

 

[kevplumb]

the wires will be connected to the high limit stat you need to find it and prob reset it

 

[benji]

Hi,

Are you talking about the wires connected to the "Overheat Cutoff Connector"?

 

[kevplumb]

yup

 

[benji]

How do I reset ??

 

[kevplumb]

usually there is a button between the terminals on the stat

 

[benji]

Hi Kev,

I cannot find a button between the connectors. However I have looked at the servicing instructions and it has told me where to test for "continuity".
What is continuity?

 

[kevplumb]

if theres not a break in the wiring etc ie its continuous

 

[breezer]

but you cant check that since you have already said you do not have a meter