Very little actual servicing of the high-limit switch is required.
However, it is good to know the location of the switch when
working on the heater. Typically, the switch is located on the
heat chamber face or at another similar location at the
burner end of the heater. Some models may have the switch
located on the housing at the motor end of the heater, or on
a bracket near the burner.
Depending upon model, and design sequence, some
heaters used a spacer between the legs of the high limit
switch and the heat chamber. These allowed the switch to
open at the proper temperature. If your heater is so
equipped, insure the spacers are reinstalled prior to
mounting the switch. Spacer thickness may vary with model
and design. Refer to appropriate parts list for part number.
Other heater designs may have the switch mounted without
spacers directly to the flat of the heat chamber face or to
formed offsets which act as spacers. Familiarize yourself
with switch mounting characteristics.
Specifically relating to the AB200 heater, the high limit
consists of capillary and switch mounted to a bracket near
the burner. If switch replacement is necessary you will need
to route the capillary behind the burner, and then across the
heat chamber face, allowing 12 inches of capillary to be in
contact with the heat chamber. The capillary is held in
position by tabs that are formed from the heat chamber.
Insure you have also installed the spacer clips on the
capillary to prevent premature high limit tripping.
Servicing
Instructions
August 1999
8.1-1
1
Spacer
Without
Spacer
Offsets
High-Limit Switch Replacement
