My pilot lights and stays alight. The electrode continues to spark - which it shouldn't , however the main burner will not light. After discussion with friends it would seem that thermocouple is not working properly.

The problem is that the boiler doesn't seem to have a thermocouple?
any ideas?

Mark Williams, October 2006

My glowworm ultimate wont ignite at all, a very little click for the spark, boiler sounds if is working, but wont heat water !

Steve Roberts, January 2015

my boiler only startsup if i keep my finger on the reset button any ideas

phil, January 2012

I have a glowworm ultimate, we had to take one of the radiators off to flush it as it was not heating up but when we re-connected it and turned the central heating back on the pilot light would not come on but the fan was going round. So we turned it off like it said and when we turned it back on the pilot light kept going off and then coming backback on. the heating stays on for a while and then it goes off. Any help please what this could be.

kerry, October 2010

my gloworm ultimate boiler will not fire up for the central heating , but is perfectly ok for hot water any idea's

malcolm hull, October 2010

boiler won't fire up - pilot ok.

Loz, March 2010

-i have the same problem for the last 3 days me and my 5 kids have sat in the freezing cold and i dont know what to do i tried everything i was asked if it was on a timer but i no theres a box on my upstairs wall with a dial and red and blue button.i always thought it was set to constant but the boiler on turns on wen it wants to my last resort was to phone the council to get a call out,as we cant sit it cold anymore.any ideas how the red and blue buttons on the timer have to be set as ive never had a manual wich explains this i just want to be able to turn thermostat dial on downstairs and on comes me heating and turn it off by the dial when i dont need heat.please any ideas n answere would be very much grateful and appreciated right now.many thanks
carla.

carlaB, February 2010

oil boiler check flame probe checck uv photo cell most of all check you have got some oil and filter is not blocked it also could be that the air damper has moved causing the flame to lift off the probe or cell

john boy, October 2009

sounds like its the flame probe or lead to me if the pilot is lighting then the fan must be running and has already made the air pressue switch check for a good flame and that the lead from the probe is ok if the lead is ok and flame on pilot ok then its the board

john boy, October 2009

I have an old oil heater which was working fine till today when it first got cold enough to turn it on. When we tun it on the motor fires up and you can see the glow as if it is trying to fire up the flame, but no flame. After a few minutes it shuts off. What could the problem be? Could it need to be bled?

Bob, October 2008

flame retification failure your board is knackered

Derek Davis, December 2007

I have a glow worm space saver, everything was working fine last night, but today the boiler wont fire up, the pilot light is lit and everything looks ok.
But when I try to get it going it just wont fire up.
Any suggestions please, before I call in an engineer tomorrow?

Marlene Smith, November 2006

trust me, check the pilot is big enough, as ultimates are notorious for this fault and its usually the pilot injector although the electrode and lead can be suspect as has been mentioned before, as for thermocouple, there is not one as you have said so hi spec plumbing are wrong i am afraid.
BG ENGINEER FOR 16 YEARS

MIKE, November 2006

It will probably be the spark electrode lead. once the pilot lights it rectifies the current telling the pcb the pilot is on and is ok to light the main burner. First i would replace the electrode lead if is still does not stop sparking and fire up then the pcb is at fault

Paul, November 2006

the thermocouple is working cause you have a pilot light. the thermocouple is there to keep the gas valve open if the pilot gos out the gas valve will shut. it sounds like a poss fault with pcb board, check to see if the fan in the top is working you'll hear it before the burner lights to remove any gases still in the flue. if the fan does not work it could be knackered or jammed, which will stop the burner cutting in.

hi-spec plumbing, October 2006