Glow Worm Ultimate 40FF sparking but no flame - help

[mattluckhurst]

Firstly hello to everyone out there - I hope someone can help me.

As per subject, my boiler has suddenly decided to stop working. The pilot is sparking, but is not lighting. One thing I noted was that the boiler is trying to light (sparking) even though I am not calling for heat ie. CH & HW are both off at the programmer - I don't know if this is normal. I have also tried lighting with heat on demand & no difference noted.

Now I have read up on some similar occurrences on this forum but none exactly matched my scenario.

I have neons 1, 2 & 3 lit but not 4 so some sort of injection/firing problem (so I am reading from the manual). The fan is running when trying to ignite.

I have dismantled & checked the pilot injector for blockage but the 2 very fine holes are present & not blocked.

I have put the flame from a lighter on the pilot electrode & when I get it exactly in the right place I can get the sparking to stop & you can hear what I assume is/are the solenoid/s clicking but neither the pilot nor the main burner light.

To me, it appears that there is no gas to the pilot & possibly the main burner - wouldn't the main injector light when putting a flame at the pilot to achieve flame recognition ie. when the spark stops ? I assume checking the actual gas supply to the boiler is strictly for a qualified professional ?

Thats about as much as I know - other than the boiler must be about 10 years old & has certainly not been serviced for at least the last 6-7 years

Thanks in advance for any help offered & sorry for the long post.

 

[namsag]

Firstly you have 2 probs
For the system to try and light with no demand suggests a microswitch is sticking on one of the motorised valves,
Second
your gas valve has prob got two seperate solenoids on it. both the same one for pilot gas one for mains gas,
Take them off and Swap them over and your pilot should light this will confirm faulty solenoid and only needs replacing cost about twenty quid from www.gas-spares.co.uk

 

[malkie]

is there 230 at solenoid when its trying to spark

 

[Steve69the69Gas]

I had very similar problem.
The fault was ..... the 2 spigots on the fan housing -- 1 was blocked with sh*t.
I put a small diameter hss bit through to clear the hole (by hand) and whoomf, it stopped the APS from working of course.
Try it - nothin to lose.

P.S you must be a corgi to do this!

 

[DP]

Could it not just be blocked pilot injector?

 

[namsag]

Yep should be 240v(dont think these are 24v) as it attempts to light.

jUST reread your post , as in sparking stops when you hold lighter to the electrode and you hear solenoid lift this SHOULD bring on the main burner and light off your lighter are you sure the gas is on at ,meter or if ETM meter its not locked out

 

[mattluckhurst]

Thanks for all the advice chaps.

Namsag
You mention a sticking microswitch on motorised valve - where is this switch/valve located ?
Yes there are 2 solenoids - how easy is it to swap them over ? Is it just a case of isolating AC supply & unplugging or is it a bit more technical. I am a complete newbie to this & have only learn't what I have from this forum & playing with (probably not the right word) the boiler.
You later mention about gas supply & ETM meter locked out - what is ETM please ?

malkie
I will be attempting to measure the volts at the solenoid next.

Steve69the69Gas
I don't understand - if the fan is working, then the next stage is ignition. If the fan circuit was sensing a problem then the ignition circuit wouldn't be allowed to start (or am I completely wrong ?)

DP
Injector has been removed & the holes were visible. Or are there other parts to the injector that also need checking.

Thanks guys - your help is appreciated & I am not questioning your knowledge/advice - just trying to understand more about it.

Matt

 

[malkie]

If you have 240 at the gas valve thenits the gas valve as you have cleared the pilot injrctor out and if its clear then i cant see any way past the gas valve as its doing what it should until pilot is asked to light so if 240 to g/valve then its gone down

 

[namsag]

ETM is eletronic token meter ie comes with little credit card type thing you buy gas on.
No offence meant but if you cant recognise a motorised valve then best get someone in your out of your epth

 

[g20]

you dont have to be corgi registered to "play" with gas appliances or pipework if its your own house so go for it have a mess around!

But if you have "tricked" the flame rectification circuit into opening the solonoid with the lighter, and you heard the "click" of it opening then the main burner should have lit. have you had any work done recently on the gas pipe? try disconnecting the compression joint where the gas pipe joins the boiler a little and test if there is gas at the applaince and purge it.

 

[mattluckhurst]

Update.

Had an engineer round (friend of a friend) - after a few checks they seem to think that it is the PCB at fault. They said that with the programmer off the wall (disconnected) the boiler was still trying to light, which it shouldn't.

He had a quick look at the PCB but couldn't see anything obvious. He said that it is probably worth getting the board checked (where I work we have electrical/electronic bods) before buying a new board.

Does anyone know the typical/likely causes of board failure - I have read that these boards were prone to failure. There isn't a huge amount of parts on the board but he suggested it could be a stuck relay contact. I will also check for dry solder joints.

Thanks

 

[Agile]

I am reluctant to advise anyone who is not proved competent to work on gas.

Putting a lighter flame to the sparking pilot could have given you a nice shock ! It would also have brought on the main burner if everything else was correct.

It sounds to me as if there may be a fault on the gas valve apart from the PCB.


In my view it needs a competent CORGI.

Tony

 

[Rayzinzerbar]

you dont have to be corgi registered to "play" with gas appliances or pipework if its your own house so go for it have a mess around!

no but you have to be competant

 

[Agile]

you dont have to be corgi registered to "play" with gas appliances or pipework if its your own house so go for it have a mess around!

But if you have "tricked" the flame rectification circuit into opening the solonoid with the lighter, and you heard the "click" of it opening then the main burner should have lit. have you had any work done recently on the gas pipe? try disconnecting the compression joint where the gas pipe joins the boiler a little and test if there is gas at the applaince and purge it.

That was a very irresponsible statement for him to have made.

Although he seems to know a little about boilers, I must conclude that he is not CORGI registered himself otherwise he would acted more responsibly!

Tony