Dometic thermostat problem

[ronbazin]

I have a question about the thermostat on my Dometic 2-way fridge (1988 model RM190).  Is the flame in the burner suppose to increase and decrease in size when the thermostat is turned from low to high?  Is it suppose to change gradually as you move through the range of settings, or abruptly at certain points?

I have a problem with the fridge flame going out over time (from a few hours to a day after lighting).  I've checked the gas pressure (11" w.c.) and it's fine.  I also found there could be a problem with another part of my fridge (see post "Fridge flame failure device stays open") which may or may not be related to this potential thermostat problem, or with the issue of the flame going out over time.

I'm wondering whether the thermostat might be the problem for the flame going out over time.  When the fridge is first started, the flame stays exactly the same size from high through to low on the thermostat dial.  It gets really small only when I dial the thermostat almost to 0.  I also tested the thermostat once the fridge had reached a cold temperature (water freezing in a cup placed in the fridge).  At that point, the flame changed size only once across the whole range of settings, and that was at about the number 4 or 5 setting (when the flame changed abruptly in size, not gradually).

Any insight into whether this is even a problem, whether it might explain why the flame goes out over time, or how the flame should respond to changes in the thermostat would be much appreciated.

Thanks,

Ron

[austinado16]

That's exactly what the flame is supposed to do.  

The thermostat is basically an on/off switch for gas flow......except that the "off" is really more a "tiny leak" than a true gas-off.  So you get a nice blue flame when the t-stat calls for more cold, and a short blue flame when the t-stat closes down.  And.....that "on/off" position changes as the fridge temp drops inside.

If you have a flame that's going out after a while, you probably need to clean the burner tube inside, the chimney, cross-over pipe and air supply pipe, and the gas oriface.  You may also have debris inside the t-stat's passages.  The "off" passage is really small, so it may get clogged up.

[ronbazin]

Thanks austinado16.  I've replied through my other thread (see fridge flame failure device stays open).