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New Member
Nov 28, 2021
We have a Heatilator NDV4236I fireplace that we were told had a bad control panel. We replaced the Dexen control module and now when we turn on the wall switch we get the pilot light to ignite but the main burners never fire up? Any thoughts on what to check next? The local fireplace company wants 500.00 to come out. Any help?
Can you post a pic of what the valve looks like?
Sometimes, the valve innards get stuck when they've been inactive over a summer season.
Try taking a plastic handled screwdriver & give a sharp "rap" on the valve where the "NAT" is stamped.
Does that help?
Sometimes, the valve innards get stuck when they've been inactive over a summer season.
Try taking a plastic handled screwdriver & give a sharp "rap" on the valve where the "NAT" is stamped.
Does that help?
I tried that and still nothing with the main burners
Have you pulled the burner, removed the burner orifice & cleaned the gas line behind the orifice?
I have the same fireplace Heatilator NDV4236I-B unit discussed in this thread and it was installed in 2017. It worked fine the first year for about a total of 2 hours of use. It then sat idle until fall of 2020 and the main burner would not lite. So finally I got around to testing the unit which has an IPI ignition system (new to me).

With the IPI system, I verified that the pilot lights works great and stops sparking quickly and there is 1.62 volts at the green spaded terminal on the gas supply valve to open the main gas valve but no main gas evident in the fireplace. Prior to verifying voltages, I did verify that both the pilot and main burner solenoids had an resistance (35 ohms and 66 ohms, respectively) and are NOT an open circuit.

I have tried taping the gas valve kind of aggressively with NO main burner lighting.

I have NOT verified that the burner nozzle is unplugged or possibly the burner area is plugged up. I was hoping that someone could provide some insight on how to get under the log floor in this fireplace to lift / remove the main burner exit plate for access to the main burner nozzle area (not accessible from the bottom access area with all of the controls). Any help would be appreciated to eliminate a clogged nozzle, as a possible problem with a unit used infrequently.

I see that the originator of this thread stated he cleaned "his out" but I am confused on how much hardware to remove to gain access to this burner area. I have allot of trouble shooting experience with Heat & Glo units but this burner configuration / valve assembly #16 looks very confusing in the owner manual part breakout.

Also, If someone has a good idea on HOW to test if the main gas valve is opening or not, it would be appreciated.
In order to access the burner orifice, you will need to remove the logs.
Once they're out, there are usually AT LEAST (4), 1/4" hex head "zip" screws holding
the burner pan down, but there may be more. Remove them & the burner should lift up slightly.
Take a peak underneath & see where the burner tube goes to the orifice.
It may have to be pulled sideways or straight out the front to disengage
the tube from the orifice. The orifice can be removed with a 1/2" (13mm)
wrench or socket. Generally, the orifice itself doesn't get blocked. the blockage,
usually a spider's nest, is located just behind where the orifice is installed.
Sweep that area with a Q-tip or a pipe cleaner. Reassemble everything &
reset the air shutter according to the openings in the manual. Hafta do some
research to find the valve specifications...
I was sure hoping that you would make an input since you are such an asset to the forum from your numerous and thoughtful recommendations. Thanks so much for your input to gain access to the gas nozzle area. I will perform those steps and report my results on the forum. OBTW, it is the standard Dexen gas valve for the IPI system (750-500) that is shown in this tread also.
Feel free to message me if you hit a glitch.
I've been inside a LOT of these units,
especially for Hearth & Home technologies & their brands.
I don't know it all, but I know where I can access info.
Their various brands are what I worked on for the last 3.5 years.
Thanks so much for the message offer and it is definitely an insurance policy to go forward. Hope to start tear down tomorrow afternoon and I will keep you informed.