Dometic AC/LPG fridge hard to start on Propane

[clemon]

Hi folks. The Dometic AC/LPG fridge in my '92 Southwind is difficult to start on propane. Once it's running it stays that way, but usually needs 3-4-5 tries to get the thing to kick in. I suspect a dirty/worn ignitor (?). FWIW, the fridge runs fine on AC shore power.

I have never fiddled with inner workings of fridge, so a certain level of detailed instruction may be required on my end.  ??? I am fairly handy, but unfamiliar with the unit.

Thanks in advance.

 

[donn]

Does this happen when you firat turn it on?  I would bet you turn your gas off at the tank when you get home, and turn it back on to cool the refer?  Try purging the air out of the system using a stove to burner first.

 

[clemon]

Hi donn. I had thought of that one, because I do exactly what you think I do! The propane tank gets shut off when not in use. I have tried lighting a burner first to purge air from the gas line, but it doesn't seem to make a significant difference to the fridge....??

If I know what to look for I think I can manage a bit of dIY servicing - clean or swap out the ignitor, etc. Maybe if I get someone to turn the fridge on while I've got the exterior vent panel off I can figure out what's going on. FWIW I have the same issue with my water heater, though that one seems not to care if the propane has been running for a week or not! 

Why do I forsee a trip to the parts store?? 

 

[donn]

Sounds to me like it is time for a pressure test of your gas system.  If the regulator is going low it could present as the problems you describe.
You could also try a couple of other things.  Using a brush, clean the chimney out of rust and/or debris.  Then take the orofice out and clean it with some soap and water.  Finally using an air compressor blowmout the area around the burner.  Being sure the thermalcouple is actually in the flame

 

[Gary RV_Wizard]

The igniter either sparks or it doesn't. If it is sparking (sounds like it is, since it lights fine once you get it going), there is no need to clean or replace. And the burner tube must be clear as well, for the same reason

It sounds to me like you simply have to wait for the gas to reach the igniter. The gas feed valve doesn't open until the igniter cycles, so it takes awhile for the gas to push the air out of the line to the fridge.  Burning the stove gets gas into the main line, but doesn't help much on the feeder to the fridge, which may be teed off well away from the stove.  I suppose you could take a wrench and manually open the fridge gas line  where it enters the valve so it could purge, but that seems like a lot of work when several clicks of the starter does the job.

 

[DrGlitch]

My old Dometic refrigerator model RM2310 started great.  The cooling system finally developed a leak and I replaced it with a brand new unit of the same model.  From day one, the new unit didn't start for crap after it sits unused.  It can take 30 or more attempts, so I'm worried the ignitor is going to wear out.

Isn't there some kind of adjustment on the unit for this?  I can't be the first person to have had this problem.

 

[clemon]

Update: I had our rig out for the first time this season last weekend. I did get it to light last week after priming the system (getting the gas flowing through the system again by lighting a burner). We had a bit of trouble getting it to light for our run to the CG (about an hour and a half drive) - took about 30 minutes of try-and-retry while on the road). It had no problem switching automatically back to LP after being on A/C power for the weekend though.

Maybe it's too windy on the road to reliably light? Seemed to work fine while parked on a level spot.