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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22519
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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Payne gas furnace 394JAW036045 igniter keeps sparking while

Customer Question

Payne gas furnace 394JAW036045 igniter keeps sparking while pilot light is on but does not start the main burners. I know its time or past to replace the furnace but can i get it running for now?
Submitted: 1 year ago.
Category: HVAC
Expert:  Phil replied 1 year ago.


Please attach a well focused, close up photo of the wiring diagram glued inside the service panel,you can use the paper clip icon at the right end of the toolbar at the top of this dialog box,Include a picture of the thermostat wire connections to the printed circuit board in the same area.

If there is no paper clip icon, look for the '+attach files' link at left of your send button.

The problem is that either the gas valve is bad or the printed circuit has failed, these repairs are in the $500 range if you have the work done. Parts cost in each case will be in the $200 range if it is a furnace build since 1985 or so. If its older costs will be somewhat less.

With an older furnace you should have 2 carbon monoxide detectors in the house.

If I miss you tonight I will pick your response up first thing in the morning.

Expert:  Phil replied 1 year ago.

One of our other experts here says that the unit may have the 3 wire pilot with warp switch.

Pilot light could be confirm....with pilot lit jump terminal 1 to terminal 5 on gas valve.

If it starts pilot is bad. If it does not it is gas valve. I will know for sure when you can get me a photo of the wiring diagram.

We can go from there.

Customer: replied 1 year ago.
Here is the circuit diagram and the picture of the igniter and yes it has three wires to it besides the spark wire. The furnace is running now so I must have an intermittent problem.
Customer: replied 1 year ago.
PS thanks
Expert:  Phil replied 1 year ago.

Hello again David,

After seeing the diagram I am not recommending that you trouble shoot or work on that furnace yourself. It will not be an easy trouble shooting process, and there will be some risks that I do not recommend you take.

We will have to keep an eye on it, for now put some kind of spacer between the high tension sparking lead and sheet metal, the high voltage insulation breaks down a bit sometimes and can prevent sparking at the ignition rod... that would be a safe enough measure.

It is also possible that your furnace has a vent damper, as shown as an option on the wiring diagram, you may want to make sure the damper is opening if it has that option.

Beyond that measure this is likely to be a risky situation for you to attempt any repairs on, parts may not even be available. I do not recommend jumpering terminals 1 and 5 on the gas valve as a test in this case either.

Call those people on the phone monday, with the brand and model number of your furnace and ask if they have the spark ignition switch module and gas valve for that furnace... if they do not have it, it might be time to start thinking of a replacement furnace.

Keep me posted, we can go from there.

Expert:  Phil replied 1 year ago.

Do not buy the parts from Furnacepartsource now, just check to see if they have them.

Customer: replied 1 year ago.
Furnace Source parts have the spark ignition module..134.50 the guy sent a picture, attached, and it looks like the same part a in the furnace.
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Expert:  Phil replied 1 year ago.

Thanks, I have asked another expert here, Billy, with over 11,000 successful answers here, and perhaps the most experience on the older Brant furnaces to look your situation over.

If he picks your question up, I will opt out, be sure to give him the positive rating if it works out for you. I will keep tabs on this to make sure you get the situation resolved, I just want Billy to look this one over given his background on these units.

Expert:  BillyHvac replied 1 year ago.


My name is Billy.

This 3 wire pilot works off a bimetal warp switch. The unit gets a call for heat and sends 24v to pilot terminal on gas valve and also to the ignitor box (black box). Once the pilot lights the side starts to heat up and eventually warps and sends power to the main gas terminal.

99% of the issues with this unit is the pilot. The spark tip electrode in the white ceramic attached to the pilot should also be changed...the reason it keeps sparking is that the electrode no longer senses the pilot is there and keeps sparking. a new spark tip will stop sparking as soon as the pilot is lit.

Customer: replied 1 year ago.
It look like the spark wire goes right into the spark control box, no terminal, does that mean I need to replace the whole assembly?
Expert:  BillyHvac replied 1 year ago.

you have 2 issues:

the warp switch is not reliable. That means replace the 3 wire assembly.

sparker keeps sparking. That means replace just the ceramic cube with electrod tip...the cable and box can stay

electrode -