heatslave 20/25 oil combi boiler - burner wont light!

[mulls]

Hi all,
I hope you can help. I have the above boiler problem.

About 5 weeks ago, all power to the boiler went down. With one thing and another, I didn't look into this until last weekend. The first thing I checked was the fuse in the switched spur which I found to be of the wrong rating and had blown. Fine, I thought. I replaced with a new fuse of the correct rating and switched on. Power came back - great.

I then switched the heating on and though the burner motor started, it didn't ignite? I took the burner out, cleaned it up etc and replaced it but it still doesn't light. I do hear a "click" at the point it should fire up but I cant tell whether this is just the solenoid or an actual spark. When taking out the burner, I do see oil where I'd expect (on the nozzle and around the burner/flame appature) so I don't think its a problem with the fuel - it's just not being ignited. It was all working fine before the fuse blew.

Can anyone advise me how I can test for a spark at the electrodes? Can anyone advise what the most likely cause of the problem might be - electrodes/ignition transformer/solenoid - I can then start replacing bits!

Thanks for any help you can give.

 

[Terrywookfit]

If you have no spark then check the IGN TXFR!

Some times you can see a bulge on the case!

If wrong rating of fuse was fitted the control box could also be damaged!

 

[mulls]

Thanks for that. The ignition transformer LOOKS fine and the original fuse was a lower rating than it should have been so I hope the control box is alright.

I'll order a replacement transformer just in case but for future reference, is it possible to test it using a multimeter? Should I expect a certain resistance?

Are there any ways of checking for a spark at the electrodes which of course I cant see when the burner is in place? Can I cut off the oil and then test it when it's not in position?

Thanks.

 

[Terrywookfit]

Wire it to a known fused supply!!

IF you have mains in you should have sparks!!