Heat and Glo natural gas fireplace will not ignite

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Partlowr

New Member
Nov 12, 2018
4
Chicago
Hello, this is my first post but I have been poking around on here for the past week or so trying to troubleshoot my issue.

My trouble started the end of last winter, my natural gas Heat and Glo which is approximately 15 years old started just going out and the restarting itself sometimes followed by a large "WHOOMPP!" when it reignited. I shut it down and turned the gas line off and figured I'd look at it over the summer. Now it will not even ignite at all. Summer turned into fall and I called my local Heat and Glo service shop a couple weeks ago and they are booked out until January. I'm pretty handy so I figured I'd try to see if I could fix it myself. I found this great Forum and various threads walked me through a lot of troubleshooting.

My pilot light stays lit and there is 3 large flames down there so I have gas/fuel and good flame.

So far I have thoroughly cleaned off the thermocouple and thermopile with fine sandpaper and a scotchbrite pad, they were a white color with build up but now they are nice and silver. Unfortunately when I went to fire up the fireplace it still didn't light.

Next I replaced the wall switch, this did not work either. I even tried touching the wires together bypassing the switch and got nothing, not even a spark.

Where should I look next? Any diagnosis I've missed based on what I have described and tried this far? Thanks in advance.
 
Find yourself a multimeter & check the millivolt (mV) output on the thermopile.
With ONLY the pilot on, it should read 500 - 550.
When you turn the burner to ON, you should hear a "CLICK" from the valve
& the mV should drop to 200- 225.
Do that & tell us what you found.
 
Find yourself a multimeter & check the millivolt (mV) output on the thermopile.
With ONLY the pilot on, it should read 500 - 550.
When you turn the burner to ON, you should hear a "CLICK" from the valve
& the mV should drop to 200- 225.
Do that & tell us what you found.
Is that something I can just pick up at a Lowes or Menards? I'll try to grab one tomorrow. Thank you
 
Yes, multimeters are commonly available in big box stores these days.

You need one that is sensitive to read down to a few millivolts --- 1000 millivolts=1 volt.

The WHOOOMP noise you describe is called "delayed ignition." That occurs when the pilot light doesn't light the main burner PROMPTLY, as soon as the main burner gas switches on. The main burner gas accumulates in the fireboox until it is finally touched off by the pilot light ----WHOOOMP! That can singe your eyebrows under the right conditions!

The most common reason for delayed ignition is a poor pilot flame. And the most common reason why a gas fireplace wont light when the switch is turned on is a dirty pilot burner.

So I suggest you look carefully at the condition of the pilot flame for the likely source of your problem. The pilot flame should look like a small, sharp blue flame, like a small blowtorch.

If the flame is a soft blue flame, easily blown around or has yellow tips, that a good indication that the pilot burner is dirty and needs to be taken apart and cleaned. Let me know what you see.

And keep an eye out for how fast that main burner lights up. Keep your head away from where that gas flame can reach out and touch you if it doesn't light promptly.

As a gas fireplace repairman I kept my hand on the gas control valve, ready to turn the valve to the pilot position if the main burner delayed in lighting. But that takes some practice! Keep your face out of the fire!

I was the guy who DIDN'T work for a fireplace shop, but who was available to come out promptly to repair people's equipment, but I retired eleven years ago.
 
Yes, multimeters are commonly available in big box stores these days.

You need one that is sensitive to read down to a few millivolts --- 1000 millivolts=1 volt.

The WHOOOMP noise you describe is called "delayed ignition." That occurs when the pilot light doesn't light the main burner PROMPTLY, as soon as the main burner gas switches on. The main burner gas accumulates in the fireboox until it is finally touched off by the pilot light ----WHOOOMP! That can singe your eyebrows under the right conditions!

The most common reason for delayed ignition is a poor pilot flame. And the most common reason why a gas fireplace wont light when the switch is turned on is a dirty pilot burner.

So I suggest you look carefully at the condition of the pilot flame for the likely source of your problem. The pilot flame should look like a small, sharp blue flame, like a small blowtorch.

If the flame is a soft blue flame, easily blown around or has yellow tips, that a good indication that the pilot burner is dirty and needs to be taken apart and cleaned. Let me know what you see.

And keep an eye out for how fast that main burner lights up. Keep your head away from where that gas flame can reach out and touch you if it doesn't light promptly.

As a gas fireplace repairman I kept my hand on the gas control valve, ready to turn the valve to the pilot position if the main burner delayed in lighting. But that takes some practice! Keep your face out of the fire!

I was the guy who DIDN'T work for a fireplace shop, but who was available to come out promptly to repair people's equipment, but I retired eleven years ago.

Thank you very much for you help so far. My flame is more orange/yellow than blue and it does not appear to be torch like. My brother-in-law is going to bring over a multi-meter tonight after work . In the mean time I just located and ordered the entire pilot assembly( (broken link removed to https://www.stove-parts-unlimited.com/search-results?q=(4021-736)) ), it was only $79 so I figured why not buy it and replace it while I've got everything opened up and taken apart.

I do have one more question. I am going to go ahead and replace the wall switch as well, is it a special type of switch or will any Lutron or Leviton wall light switch I can pick up at Home Depot work?
 
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Thank you very much for you help so far. My flame is more orange/yellow than blue and it does not appear to be torch like. My brother-in-law is going to bring over a multi-meter tonight after work . In the mean time I just located and ordered the entire pilot assembly( (broken link removed to https://www.stove-parts-unlimited.com/search-results?q=(4021-736)) ), it was only $79 so I figured why not buy it and replace it while I've got everything opened up and taken apart.

I do have one more question. I am going to go ahead and replace the wall switch as well, is it a special type of switch or will any Lutron or Leviton wall light switch I can pick up at Home Depot work?
 
Sounds like cleaning the pilot orifice is the likely problem. You can probably do that in a half hour and save yourself the cost of the pilot assembly.

You might take a careful look at the pilot flame again so that you can compare that to the appearance of the pilot flame with a clean orifice.

Any wall switch will do. Any wall switch, designed for 120 VAC, can also quit working at any time, too.

Using a switch designed for 120 volts with a half volt can occasionally produce unreliable operation. That was a fairly common repair on gas fireplaces, although cleaning the pilot orifice was the #1 cause of burners not lighting.
 
Yes, multimeters are commonly available in big box stores these days.

You need one that is sensitive to read down to a few millivolts --- 1000 millivolts=1 volt.

The WHOOOMP noise you describe is called "delayed ignition." That occurs when the pilot light doesn't light the main burner PROMPTLY, as soon as the main burner gas switches on. The main burner gas accumulates in the fireboox until it is finally touched off by the pilot light ----WHOOOMP! That can singe your eyebrows under the right conditions!

The most common reason for delayed ignition is a poor pilot flame. And the most common reason why a gas fireplace wont light when the switch is turned on is a dirty pilot burner.

So I suggest you look carefully at the condition of the pilot flame for the likely source of your problem. The pilot flame should look like a small, sharp blue flame, like a small blowtorch.

If the flame is a soft blue flame, easily blown around or has yellow tips, that a good indication that the pilot burner is dirty and needs to be taken apart and cleaned. Let me know what you see.

And keep an eye out for how fast that main burner lights up. Keep your head away from where that gas flame can reach out and touch you if it doesn't light promptly.

As a gas fireplace repairman I kept my hand on the gas control valve, ready to turn the valve to the pilot position if the main burner delayed in lighting. But that takes some practice! Keep your face out of the fire!

I was the guy who DIDN'T work for a fireplace shop, but who was available to come out promptly to repair people's equipment, but I retired eleven years ago.
bob i so much admire you guys. it takes a lot of guts to strike out on your own I sold and owned my own restaurant supply business. i probably sold 100 gas control valves to customers because their ovens in their stoves would eiither light or stay on. Many many thermocouples such easy fixes but so many stupid people in school maintance! i loved every minute of it and was good at it!!