Glow worm Ultracom trips out

[j1mm1nycr1cket]

Hello All,
My Glow Worm Ultracom HXI (re-badged as British Gas 330) stopped working during the night. I woke up to find it had tripped out the mains.
If I turn it on, when heat is being requested, it only manages to stay on for maybe 5 seconds before it shuts off and takes the mains out with it.
I thought it might be the timer switch doing it because that was the 'trigger' that seemed to cause the boiler to shut down, so I replaced that, but the boiler still won't stay alive for more than a few seconds.
So I'm guessing it must be something that starts up early in the process, perhaps the fan.? Electrode.? The fault code is F1 (ignition), but that could be misleading since the boiler doesn't really have a chance to get started, it barely has enough time to get to the ignition stage before it keels over and F1 could be a number of things anyway.
My engineer (who can't come out at the moment) suggested disconnecting the pump to see if it's that. The main circulation pump in the airing cupboard has been quite noisy for some time (it vibrates quite loudly), so that could have died I suppose.?
Does anyone have any advice about what I should suspect first please?

Thanks

 

[spareshunter]

Respecfully your engineer is a twinkle for sugesting diy remedies. I would suggest asking him if he has indemnity insurance before taking any more advise from him/her. Call a boiler engineer .... Do not dabble yourself. simples.

 

[j1mm1nycr1cket]

..yeah I won't be tampering with any gas stuff don't worry. I'm more interested to know if anyone had an idea what it might be just so I can be prepared really.
I regularly do small electrical jobs around the house and disconnecting the pump temporarily is do-able safely so I may try that if anyone agrees it's worth ruling out.

 

[mogget]

I will assume it's tripping an rcd, and that it doesn't get as far as actually lighting. If not, please disregard.

You could disconnect the pump, provided you also turn the gas off at the gas cock under the boiler. Otherwise you'll be trying to light it with no way of removing the heat from the boiler.

If after this procedure it locks out but doesn't trip the mains, you will have found the culprit.

Not a gas engineer just the owner of an ultracom hxi15.

But if you're not going to be changing the pump yourself I'd let your engineer diagnose it.

Whatever you do, don't open the boiler case.

Mogget

 

[j1mm1nycr1cket]

Yes, Mogget that's exactly what happens.
So I'll disconnect one side of the pump and see if the boiler stays alive for more than a few seconds.
If necessary I will also try disconnecting the actuator in case that's the thing that's gone. I've got a spare one in the garage which came with a 3-port valve I bought on eBay, so if the actuator has died, at least I won't have to shell out for one of those