Colleague looking for help with a glow heap head scratchier.

[solutions]

A good friend and fellow gas engineer of mine who is not currently a member of the forum (at least not with gas safe private forum access) has been to a British gas 330+ / Glow worm (not a hxi this one has an aluminium heat exchanger).
The Boiler has an Ignition fault, when firing the burner ignites then immediately the gas valve is shut off then immediately opens again to repeat the process. Sounds like boiler is spluttering.
After 3 attempts, during each attempt the boiler spluttering a number of times, the boiler locks out on F1. It's not a main board fault. Probe is rectifying and there is 24 volt to the gas valve which shuts off when gas valve closes? My colleague describes it as like the board is miss reading the rectification current and instead of keeping the gas valve open closes it. My money is on it needing a better earth and I have told him to try that but have any of you wise folk come across this before or have any suggestions?

 

[SilentMike]

He checked the meter regulator ?

 

[solutions]

He checked the meter regulator ?

He didn't say so but not sure how that would affect voltage to gas valve solenoid, unless your thinking rapid pressure fluctuations lifting the flame and loosing rectification. I will pass on your suggestion. Thanks Mike.

 

[SilentMike]

Had on the other day like your describing standing pressure was fine then was dropping down to 4mb

 

[Rabbitman]

The BG 330+ is simply a flexicom and not that bad an appliance to work on, F1 simply means the appliance has failed to rectify......... Should your friend rule out the obvious ie inlet working pressure and gas valve etc then i would be looking at the following

1 electrode, depending on its age the earth rod had a habit of coming a drift on the earlier appliances

2 condensate, a problem with trap or the pipe work will cause you F1, although this should be accompanied with a gurgling sound

3 spark generator, this is the likely culprit as one its prone to failing and two it's mounted on a bracket which can become loose and interrupting the path to earth.........

It still could be a board fault but would try the cheaper options first

hope this helps..................

 

[solutions]

Thanks rabbitman. He has tried all the standard pressure testing and voltage checks. I think will prove to be an earth problem and suggested he run a desperate earth back to the board rather than trying to earth through the case. I will pass on the info regarding the condensate trap being a possible culprit.

 

[gasmanrob]

Officially glow worm aren't allowed to tell you about the faulty gas valve on that particular style boiler. Unofficially a glow worm engineer had his nose broken when the combustion door blew off when said gas valve was letting by and boiler ignited in rather an explosive fashion

 

[arran197]

Electrodes are common for failing.

 

[GrahamM]

As arran197 I would still be looking at electrodes/leads firstly due to info given.
He 100% they are not the issue?

 

[solutions]

He was back to the boiler in question this evening so expecting an update shortly hopefully with a positive diagnosis off the back of the help full suggestions from here. Yes Graham he did say he had checked the loom and electrode. I will post up any further info or any eventual outcome.. Thanks to all who have replied so far.

 

[Whyme]

If its coming on then spluttering then off and doing the same before lockout it sounds like its doing its job regarding flame proving..Have these boilers got those flaps between the fan and burner..?

 

[Mike Jackson]

Tell him to check the flue. I had a BG 330 recently where the flue seals had gone. Could be dragging flue gasses back in.

 

[mfgs]

Tell him to check the flue. I had a BG 330 recently where the flue seals had gone. Could be dragging flue gasses back in.

Was that the rear exit flue, as I have had a couple of those where the flue has just never been fitted right and it was leaking fumes.

 

[arran197]

What was the outcome?

 

[Ollieg]

My bets on spark gen. I would reset the gas valve too though.

 

[solutions]

No joy, tried the electrode but no change. He has called on a Vailant engineer friend of his who is going to take a look at it, will let you all know if there is a definitive outcome.

 

[Mike Jackson]

Was that the rear exit flue, as I have had a couple of those where the flue has just never been fitted right and it was leaking fumes.

No standard flue with an elbow and extension to take it away from window. The inner flue seals had gone and were leaking condense into the outer flue. I was called in to look at a leak and the water was dripping out of the flue.

 

[solutions]

Just to conclude this thread with the eventual outcome. The culprit was the gas valve. In this model the initial ignition solenoid on the gas valve runs on 24volt from the board but at rectification switches to 12volt to open for main burner modulated by the fan speed. The gas valve wouldn't hold the solenoid open on 12 colt and so slammed shut as soon as it rectified.
Thanks for all the suggestions everyone. And for taking the time to read the post in the first place.