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3.
Gently pull the lower half away, while keeping the thermocouple, igniter, and gas line attached.
4.
Tilt the fridge back to its upright position, with the lower half of the burner box sitting next to it.
Now you are ready for some testing.
There are several issues that could be preventing the flame from staying on. Let’s get the obvious ones out of
the way first.
1.
Is the burner assembly inside the box clean? There should be no dirt or dust inside the box.
A typical problem is wasps or bugs nesting inside your exhaust system. Clean it out with a vacuum.
Rust is okay, as long as it is not flaking off and clogging the burner assembly. Chip out any flaking
rust with a screwdriver blade. The burner should have 3 or 4 slots on the top of the tube, directly
under the thermocouple. (See image below.)
2.
Is the thermocouple’s “tip” directly over the flame slots? The tip must be over the flame for the
maximum output voltage from the thermocouple.
The vibration of the van may have caused the thermocouple to slip back, away from the flame,
reducing the voltage production. Slide the thermocouple all the way into the case until it stops against
the flange at the base of the tip.
(Thermocouple operation: inside the tip are two dissimilar metals that generate about 30 milli-volts
when heated. This voltage is used at the gas valve to activate a coil that ‘opens’ the gas valve for
burner operation. Its main safety function is to close the valve if the flame accidentally blows out,
preventing gas build up, which could lead to unburned gas. All simple gas valves on water heaters,
etc., work this way.)
3.
On top of the fridge, connect a DC voltmeter (capable of reading millivolts) across the outer copper
tube near the flange nut, and the spade lug closest to the flange nut. This will allow readout of the
thermocouple’s voltage when you heat it in the next step.
thermocouple tip
flange ‘stop’
