Testing Dometic 182B Outside Van (LP Pressure)

[coastdog]

Hi! If your fridge is lighting fine with pre heat but popping on cold starts, your mixture of propane to oxygen is probably too rich. You will get a loud ‘pop’ when this happens. As mentioned above, you can try to work around this on cold starts by ‘not’ pushing the gas safety button in until you have pumped a bunch of air to pressurize the combustion chamber and get air flowing up the chimney. As soon as you press the safety button start clicking the piezo ignitor.

Another way to start from cold (when the fridge is installed in the van) is to open the drain line under the fridge, close all the vans doors and windows, turn the ignition to accessory and turn on the front heater fan, usually to full. This creates a similar airflow through the combustion box as pre heating and prevents flooding.

Also a good idea while you have the fridge out, and the combustion box open is
make sure the spark gap between the tip of the ignitor electrode and the burner is 3/16”.

The pump upgrade kits do help with the ‘too rich’ problem a little bit.

[brickster]

Thanks, coastdog. Your advice is matching up with my continued testing. I've got it down to 20 vigorous built-in air pumps and lighting every time from cold.

I did set the gap to 3/16. At that distance, it took a little bit of fiddling to get the spark to travel to the burner tube instead of the thermocouple.

Since I have it out, I may do some more performance mods. I've already upgraded the fin fan and wrapped the exhaust in fiberglass tape.

[brickster]

I am happy to wrap this thread up.

After installing the pump mod, I can start on first click after 5-10 pumps (20-30 before) when cold. However, that is with a higher ambient temperature (~ > 55F). If it's below that temperature, only the bicycle pump on the drain tube will work to start from cold. I can live with that since I always carry it for my coolant system and will hopefully never have to start from cold.

I also discovered that the thermocouple light on the panel didn't work reliably, but I was able to get it working again by adding a few drops of electrical cleaner in the switch and working it back and forth. It's really nice to have that visual indicator again since the window is only helpful at night.

I will follow the excellent advice from John Thomas (is he on here?) regarding using all three modes and pre-cooling food, etc.


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I'll also be picking up a flue cover to prevent bugs and debris.