Fridge has intermittant operation on Propane

[BEBOP]

HI MIKE,
I was talking about it lighting. some days it lights and somedays it doesn't. Once it is lit it did fine and we were traveling all day in 100 plus degree heat and at the end of the day the thermometer was right where it should be.
Bill

[RV Wizard]

Bill, I have found the intermitant ignition has been one of these three things we have discussed. The burner is dirty, the sensor is dirty or has bad connections or the lp gas pressure is not correct. High altitude will also cause problems but I am speaking at below 7000 ft.

[BEBOP]

I am getting ready for a trip so I took the motorhome to the shop for a noise I am hearing when I go around a curve, so told them about the problem with this fridge and to fix it.
So after they had done the normal maintenence referenced above they tried it out and found it to work as it should and had it on gas for two days.
I drove to my house from the shop, 7 miles and checked the butane, found the valve open and the Sniffer on so tried to light the fridge on gas. No luck while trying 6 times, waiting one minute between each time. I then lit the stove 3 burners and the furnace and ran them for a couple of minutes or so to purge the gas line in case any air had got into it. I tried the fridge a few more times waiting over half a minute between each try. Still no luck.

I plugged in the shore power and started the fridge on 120 volts and let it run about 5 minutes or so. I then switched over to gas. It fired right up and ran as long as I left it on. I did a recycle back to 120 volts for about an hour and the freezer dropped 20 degrees so I confirmed that it is actually working.

I then cycled it back to gas and if fired right up and ran for as long as I left it on, maybe half an hour or more and the temp in the freezer continued to drop.

I would normally guess that we had a bad thermo couple but not even sure if this fridge has a thermo couple? This is the way it acted when it failed originally. It would only stay lit after it had been preheated by the electric heater, but after the second day of use on gas it only stayed lit for an hour or so and then would not run on gas again.

I Have not yet tried it AGAIN with the shore power unplugged to see if it will start on gas.

I will go pull the plug now and try to start it on gas and see what it does.

Be right back

OK I am back.

I pulled the plug, turned on the propane, turned on the gas sniffer and turned on the fridge and it switched right to gas and lit up.

I won't have any more to tell you about this until I get it out of storage next Wednesday to load for our trip. I will at that time try to light it on propane before plugging into shore power. I will let you know if it works or not.

Surely it cannot require preheating by 120 volts before operating on butane. Nobody would design anything with that kind of requirement.

Stay tuned
Bebop

[BEBOP]

this is the update I promised for this ongoing Dometic frig problem.
I replaced both of the deep cycle batteries as each of them had one dead cell. they are two years old.
Boom, the fridge fires up the first time and runs without problem.
So.........the problem was Low Voltage to the fridge controls.
All is well that ends well.
Bebop

[RV Wizard]

Bill, thanks for the update. Glad you found the problem and that new batteries giving you good voltage corrected the problem.

[BEBOP]

well as it turned out it wasn't a battery problem.
Because of this problem I extended the dometic warranty on both AC's and the fridge for a year. Just before it expired I took it in and the problem turned out to be a bad ignitor board. it was replace and no more problem.
It is also interesting that Dometic did not offer to extend the warranty again beyond this first years extension.
Oh well darn.
Bebop