Frost fighter heater repair help please

[Rancid Crabtree]

On my IDF350 LP I think I've tested or replaced nearly electric component.
This heater is on propane.
In frost fighters you tube service videos they remove the burner and test the igniter by cycling heater with gas off and burner pulled out.
When my burner is in the burner indicator light comes on and power goes to the gas valve for about 5 seconds like it should but no spark as far as I can tell.


But when I remove the burner and lay it out to watch the igniter rod while sparking then the burner indicator light never comes on and the controller never power the gas valve.

I hope that makes some sense. I'm hoping one of you might be experienced on these heater. Any help is appreciated.

[dewalt18]

Pretty vague description of the sequence there. Double check all electrical connections, and make sure that the spark igniter isn't making contact with anything it shouldn't be and grounding out, causing it not to spark

[CaberTosser]

If you have the burner removed when checking for spark remember that the burner would normally be grounded to the unit, so if its not either in contact or using a jumper to ground it to the chassis, it might not spark for your test. I've never worked on a frost-fighter, but the same principles apply.

[troutbug]

I know on frost fighters and other brands I have had mercapton bugger up the system if you do not have an oil trap on it. Everything would power up, try and ignite but due to the mercapton plugging the valve etc it did not have the fuel to ignite.

Have you cleaned the Photo Cell? If it cannot detect ignition, it will not fire up

Are the electrodes clean?

Is the water colum set on the regulator feeding your heater?

[Rancid Crabtree]

Thanks for the suggestions guys, I have got the spark system working now.

I'll see if the system will fire up tomorrow, if not I'll have to trouble shoot the gas supply system.

[caver77]

That's harsh! Will keep and eye out.

[Frost Fighter]

When you pull the burner assembly out and don't put the cover back on this causes the combustion air to spill out and not engage the air switch which allows the ignitor to come on. Those ignitors are famous for cracking the insulator underneath the compression nut which causes the ignitor to short out and robs the stength of the spark from the ignitor tip.As far as checking your gas if you don't have a manometer allow the unit to go through its cycle and as soon as the ignitor has shut off take a sniff of the chimney where you should smell gas which is being purged out of the combustion chamber. If you smell gas then it's your ignitor . Hope this helps.

[Rancid Crabtree]

Originally Posted by Frost Fighter

When you pull the burner assembly out and don't put the cover back on this causes the combustion air to spill out and not engage the air switch which allows the ignitor to come on. Those ignitors are famous for cracking the insulator underneath the compression nut which causes the ignitor to short out and robs the stength of the spark from the ignitor tip.As far as checking your gas if you don't have a manometer allow the unit to go through its cycle and as soon as the ignitor has shut off take a sniff of the chimney where you should smell gas which is being purged out of the combustion chamber. If you smell gas then it's your ignitor . Hope this helps.

Thanks Frost.
That helps a lot. I replaced the igniter rod and used a jump wire to bypass the air proving so that I could verify the spark working while the burner is out (with gas valve off)
I'll see how it goes tomorrow and may post back with further questions.