Ideal Mini C24 Ignition board problem

[armyash]

Hi guys,

Got sent to a job yesterday, Ideal Mini C24 no CH or HW. Called technical who went through some tests.

Is the fan running? Yes
Check for 240 on air pressure switch. 240 ok

Is there any sparking at all. No I say
Check electrode leads for continuity. Continuity ok.

Techie says replace ignition board.

Ordered it and replaced it tonight. Boiler fired up on CH and HW.

Then it went off but HW was still working but then it carried on behaving the same as before no CH or HW so it seems as though something is causing the board to fail. What could be causing this?

The diverter valve motor has been bodged by someone before me, it is being held in place by pieces of a fibre washer rather than a clip. The tenant said a week ago they would have CH if the dishwasher was on. Could the diverter valve have something to do with this?

Any pointers?
Thanks

 

[dancinplumba]

Should this be in gas forum ?

 

[armyash]

Should this be in gas forum ?

My bad habit of always posting in the arms. Can a mod could move to the correct place please.

 

[Dotty]

Done.

 

[Millsy 82]

Is there a separate spark generator? If the fan is running and the air pressure switch is making and not dropping out then I would look at possible flame rectification lead arcing out? Or flame rectification probe touching burner?

 

[GrahamM]

You sure there nothing leaking and shorting out? You do mention a bodged divertor motor.

Defo sure there is no spark at all. Electrodes/leads defo ok?
Check you are getting gas at P2 on ignition?
Overheat stat & other thermistors ok? No power to gas valve if these faulty!

 

[armyash]

You sure there nothing leaking and shorting out? You do mention a bodged divertor motor.

Defo sure there is no spark at all. Electrodes/leads defo ok?
Check you are getting gas at P2 on ignition?
Overheat stat & other thermistors ok? No power to gas valve if these faulty!

The aav had been leaking but changed that also and board and surroundings was dry when I changed it.

There was no spark at all before I changed the board but then there was after I changed and it fired up fine before it suddenly stopped working again.

I was getting power at gas valve as it fired (if I remember right)

I have not checked overheat stat or thermistors in honesty.

Boss reckons fan or something is drawing too much power and blowing the board. ( I don't know If that is possible or how it could be happening)

If it was my call I would be changing the leads next. The electrode leads did check out ok for continuity though.

 

[armyash]

Is there a separate spark generator? If the fan is running and the air pressure switch is making and not dropping out then I would look at possible flame rectification lead arcing out? Or flame rectification probe touching burner?

Flame rectification could be worth checking. If the board hasn't blown.