Heat Glo turns off intermittently

[DanR80521]

Hello,

I have been having this issue for a couple years now. The behavior of the problem is that if I go to turn on my Heat Glo with the wall mounted switch, it will always turn on after a few seconds of initiating the pilot and then the gas will kick on once the thermocouple senses the flame. I believe this is called an intermittent pilot system.
All seems fine and the fire will heat up and it will stay lit for ~30mins or so. After that time the fire will slowly die out. One time I was near the fire and could see that when the fire was retracting, the pilot flame was not lit. This led me think that the thermocouple was the root of the issue. I have cleaned it before with a wire brush and it didn’t seem to make much of an impact. So this time I swapped the thermocouple in hopes that that would correct the issue. Similarly, this attempt failed as well.

One other behavior that I would note is that when the fire does stop after ~30 mins of being lit, if I go and flip the wall switch to restart it, the intermittent system will not trigger any attempt at reigniting the pilot. This behavior lasts for 20-30 mins and no matter how many times I flip the switch, it will not attempt to light the pilot. I figure this is a safety measure that is triggered when the fire place thinks there is no fire and it shuts the gas valve or perhaps some magic temperature ceiling I am hitting. After 20 mins or so, i can flip it on and it lights the pilot up without a problem.

So I think I have eliminated the thermocouple and the electrical side of the equation. Looking for any advice on what I should try to eliminate next?

 

[DAKSY]

Can you tell us what model you have?
HnG has made a LOT of different units over the years...

 

[DanR80521]

sure, the model is PIER-36TRB-IPI.

 

[DAKSY]

OK. I can't find the manual, but I believe if you pull the wall switch,
it should NOT be 120V Romex on it, but 18Ga. T-stat wire.
Can you confirm?

 

[Millbilly]

Sounds like you have an electronic intermittent system. The part you replaced sounds like a flame sensor and not a thermocouple. WAG is that as the unit is heating up a wire connection or ground is loosening and you are losing pilot flame rectification. That or your fire control module is bad. Post some pics of your pilot assembly and what those wire plug into.

 

[DanR80521]

Thanks for the feedback! Here are a few images. Let me know if you need a different angle.

- You are correct, the wall switch is not a typical romex connection. See image.
- Image 2 is the part that i replaced. After googling it, it is called a pilot assembly.
- I took 2 pictures underneath the fireplace. The first shows the orange and white wires as well as a small gas line to light the pilot as it emerges from the top. The second shows the full underneath view and where the gas line and wires terminate.

 

[DAKSY]

What happens when you jump the Red & White switch wires? Does the unit stay on?

 

[DanR80521]

What happens when you jump the Red & white wires? Does the unit stay on?

Are you wanting me to basically bypass the wall switch? tie them together and see if the fire will persist?

 

[DAKSY]

Yep. Switches can go bad. might as well rule that out.

 

[DanR80521]

Alright, I have tested this out and can rule out the light switch as the issue as it remained lit for ~ 20-30 mins and then turned off.

Not sure this matters, but when it does go out and the switch remains in the on position, the fire will kick back on in 20-30 mins without turning off/on.

 

[DanR80521]

Im fairly convinced that it is the control module. After I reworked the wall switch, I had u plugged the system and after plugging the system back in, I was able to immediately relight the fire. Normally after the fire dies, it takes a while before it will reignite. I’m going to take a shot with replacing that and will update you when I swap it and test.

thanks for the help!

 

[DanR80521]

I swapped the control module a couple days ago and it hasn’t been acting up since. Thanks for the help!