Checking output to electrode - Ravenheat 84e

[combo]

Hi,
Can anyone tell me the correct method for testing the output from a ignition pcb to the spark electrode ?

I've been roped into looking at my mates Ravenheat 84e tmz. When he creates a demand the pump and fan start but there's no sparking at electrode. I haven't looked at it yet, thought if I ignored it the problem might go away :angel_smile:. When I get there the first thing I'll do is check the air pressure switch - multimeter on volts and check whether there's voltage switching on the N.C / N.O contacts ? Assuming APS is okay, I would imagine that it's either spark electrode, electrode lead or ignition PCB ??

How can I check whther the PCB is actually sending power to the electrode, can I test at the board prior to where the voltage is stepped-up to high voltage.

Not had much breakdown experience so I may be way off mark here.

 

[lame plumber]

best check the electrode is not getting a spark is a wet finger, but no spark is easily confirmed if you have proved continuity on the electrode wire fm pcb. better start further back down the lighting cycle and check fn is working ok, aps working, no holes in aps tubes etc etc.

 

[combo]

I thought you'd get a nasty shock off a ignition on a boiler ignition.
I was gonna do a visual on lead and electrode and test continuity. Just wondered how to actually check a pcb ignition output with a multimeter, I know the 15,000v would damage most meters.

Hopefully it will be the APS or tubing as you suggest.

 

[lame plumber]

never believe all you read on the web get your sequence of testing for faults correct before you start fannying around with checking the voltage output at a spark electrode

 

[combo]

A very dangerous place the web.
Sequence; demand - fires pump/fan -switches APS - pilot valve opens and sparking commences ( not in this case ).

I think the Ravenheat is failrly primitive and is along those lines. The guy has read the book and seems to think its gonna be ignition pcb. I don't wanna order a expensive part without being able to test the original.

 

[kris]

Do your continuity test to make sure there isnt a break in the lead, you can by spark electrode testers that piggy back onto the existing one and the lead onto the tester, the tester flashes when sparking, this lets you know all is well,

 

[combo]

Ah nice one. Are these specifically for boilers or are they for the car market - testing spark plugs ?

 

[kris]

Mr combi sells them on his website, made for boilers,

 

[kris]

https://www.youtube.com/watch?v=z6WkXkcZ4y4

 

[kris]

watch this combo shows it in use

 

[kris]

fit certain sparkers,

 

[combo]

Good little tester that, only 4 quid aswell. I suppose it's just a 4 mm gap with translucent insulation material. Hopefully this will be an easy diagnostic tmz.....freebie saturday morning jobs - never a good idea !!

 

[Aquazone]

Defo make sure the APS has made, and the ignition sequence is starting. If you can hear tick but no spark check it is not arcing at the PCB or against another metal part. If all ok, take lead off electrode and check against case (stand clear) which will take out the electrode if it's faulty.

Easy checks before you get into continuity resistance etc with multimeter.

 

[kris]

My mum's boiler didn't light last week as the spark was arcing against combustion chamber as the sheath that covers the end had slid down. Old solo.