Simple Test procedures will enable you to determine whether a new cooling unit is
needed. The steps below are easy to follow and could save you money.
1) Check for an ammonia smell around the
cooling unit and inside the refrigerator.
This could indicate a possible refrigerant
leak. Check for any deposits of yellow
powder under the burner (in the back
of the refrigerator). That would indicate
that the cooling unit has leaked.
2) Determine if the refrigerator works on one
heat source but not another by testing it in
the alternate modes. Do you
get better cooling results from gas or vice-versus?
That would indicate that the problem is NOT in the cooling
3) Make sure the refrigerator is level. Sometimes
the vehicle is level but the refrigerator is
not. Place a level on the bottom of the freezer compartment
and check side-to-side and front-to-back
4) Carefully check door gaskets for proper
seal. A leaking gasket can allow enough
warm air inside the refrigerator to overcome
most of the cooling being produced.
5) Check the venting system to insure that
adequate air flow is provided at the back of
the refrigerator. Remove any restrictions
in the vents, such as filters, bird nests in the roof
vent, or smashed louvers in the wall
TESTING YOUR HEATING ELEMENT
A simple test to check a heating element is to
measure the resistance through the element
with an ohmmeter. The correct resistance, in
ohms, can be calculated if the wattage and
voltage ratings are known. (These ratings are
stamped on all Dometic heating elements.)
Use this Formula:
Volts + (Watts + Volts) = Ohms
Heating element rated 135 Watts at 110 Volts.
110 f (13.5 f 110) or,
110 + 1.23 = 89.4 ohms
The ohm reading should be within 10% of this
figure, or between 80.46 and 98.34 ohms. Use
the lowest setting on the ohmmeter which will
give an accurate reading.
When testing a 12 volt heating element, a
very accurate ohmmeter must be used because
of the very low readings that will be found.
For example, a 200 watt element will have a
reading of .72 ohms (less than 1 ohm).
A blockage within the boiler
tube, caused by too much heat
applied to the burner (oversized orifice
or heating element) or prolonged operation
of the unit when out-of-level or with
restricted ventilation. This type of
blockage consists of hard deposits inside
the boiler pump tube. This condition is
not repairable and the cooling unit must