Frustrated Heat-N-Glo owner

[mooch91]

All,

I've been in my house for 7 years and have never really enjoyed my Heat-N-Glo 6000G-LP fireplace. It was installed in the house as new construction about 5 years before we moved in. I'm convinced something is not right with the setup, but I've been unable to get assistance from a local dealer/service company and I haven't been able to figure it out myself.

I have two issues with the fireplace: (1) low flame and (2) periodic flame-out.

When the air shutter is opened all the way, as it should be for a LP unit, the flame is blue and very low. I need to close the air shutter about 75% of the way to get a respectable semi-yellow flame with a bit of height. Even with the air shutter closed this far, the flame never pops up through the designer "hole" in one of the logs.

On occasion, after running the unit for a period of time (20-30 minutes), the flame just completely dies out. It does it slowly over time until it finally turns off. This doesn't happen all the time, it's very intermittent.

I brought the service company out again last year and they did the routine cleaning and told me "all is good". They said just leave the shutter partially closed if it works. Shortly after they left, the flame died.

Thermocouple and thermopile are good (both have been replaced a couple of times over the years by me). I have literally removed the whole unit, cleaned, and reassembled. There is a low-high knob on the unit that does nothing to the flame.

My knowledge of combustion tells me one of two things - it's either not getting enough fuel, or it's getting too much air. If the designated air shutter position for LP is to be fully open, and it has a low blue flame when this is the case, I'm assuming it's not getting enough fuel. I've disassembled and cleaned what I can, but I've not gone too deep in to the valve assembly to look for other problems.

It is labeled an LP fireplace, so I am assuming it has the right orifice and valve assembly installed. Ironically, when I had a new LP range installed a couple of years ago, they left it with NG settings and we were always wondering why it never worked well until I found that a part had to be reversed for LP.

Is it worth it to just order up a new LP orifice and new LP valve and just swap some parts out to see if it improves? Or any other thoughts?

First pic is flame with shutter wide open, second pic is flame with shutter about 75% closed.

Thanks!

 

[DAKSY]

Has anyone verified the LP Gas pressure into & out of the valve?
The air shutter adjusts the Air-to-Fuel mixture & it has to be
set to perform with whatever the volume of gas is coming in.
Can you post a pic of the gas valve?

 

[mooch91]

Has anyone verified the LP Gas pressure into & out of the valve?
The air shutter adjusts the Air-to-Fuel mixture & it has to be
set to perform with whatever the volume of gas is coming in.
Can you post a pic of the gas valve?

I don't know if pressure was verified. I didn't have the benefit of being here the last time the service company came out to do their thing.

Yes, will get a pic of the valve in just one minute.

I should add that releasing one corner of the glass and letting the fire run "turbulent" for a few seconds does seem to improve the quality of the flame for quite a while, even after the glass is resecured. I don't know if this might suggest anything. I've fully opened the shutter, did this trick about 15 minutes ago, and one of the flames is dancing through the decorative hole on the logs now. Not sure if this "blows something out" perhaps.

 

[mooch91]

Picture of the valve.

 

[mooch91]

There's something with opening the corner of the glass... I would normally think that would mean when I'm opening it I'm giving it more air to burn properly, but the flame looks good even after I re-seal the glass. It's almost as if opening the glass is causing some instantaneous change to the flame (the flame seems to "switch" to high as soon as it's opened and stays that way once it's closed, until I shut it off and restart it again).

 

[mooch91]

Troubleshooting some more...

Measure thermopile voltage when fireplace is off, pilot lit: 400-500 mV.

Thermopile voltage when fireplace is just turned on, flame very low: 110-112 mV.

Open corner of glass with fireplace on, thermopile voltage rises slowly to 130 mV. As it passes 120 mV, light click is heard and flame jumps quickly to a normal condition.

Reseal corner of glass, thermopile voltage drops and stabilizes at 123 mV.

It seems like that 120 mV thermopile voltage is the key. Doesn't necessarily seem like a bad thermopile (especially since it's been changed a couple of times) - is there anything else that would cause the drop in voltage when the fireplace is first started? Pilot set too low?

 

[mooch91]

Hi all, I'm close to getting this figured out and at least have improvement to report.

My measurements above were not of thermopile voltage, wrong terminals.

I repeated thermopile voltage measurements: 600 mV when pilot lit/logs off, 200 mV when logs on.

The measurement I was taking was actually across TP/TH and TH which represents voltage drop across the switch, 110-120 mV. THis number is particularly high. I went back to my wall switch which is a LUX thermostat and swapped it out with a simple on/off switch. Voltage drop changed to 30-40 mV.

Fireplace now starts reliably each time and flame height has been consistent with shutter wide open. Flame is extending through the decorative hole in one of the logs. It starts off a bit blue and gets more yellow after about 10 minutes of operation.

I've reset the thermopile voltage to right around 500 mV with the pilot adjustment. I don't know if there is a spec for this fireplace, but 500 seems to be a common number based on what I've been reading.

Flame is still a little lower than I'd like, but I feel better knowing it's starting consistently and not turning itself off any more.