Service Guide

SCHEDULED MAINTENANCE
26


 
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R S R   
RS
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   R  R R RS
R   JS
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  Q
SR      R 
R S 
Periodically during the heating season make a visual check of
the burner ames. Turn the furnace on at the thermostat. Wait
a few minutes since any dislodged dust will alter the normal
ame appearance. Flames should be stable, quiet, soft and
blue with slightly orange tips. They should not be yellow. They
should extend directly outward from the burner ports without
curling downward, oating or lifting o󰀨 the ports.





Proper test equipment for accurate diagnosis is as essential
as regular hand tools.
The following is a must for every service technician and
service shop.
1. Dial type thermometers or thermocouple meter (option-
al) - to measure dry bulb temperature.
2. Amprobe - to measure amperage and voltage.
3. Volt-Ohm Meter - testing continuity, capacitors, and
motor windings.
4. Inclined Manometer - to measure static pressure, pres-
sure drop across coils, lters, and draft.
5. Water Manometer (12”) - to test gas inlet and manifold
pressure.
Other recording type instruments can be essential in solving
abnormal problems, however, in many instances they may
be rented from local sources.
Proper equipment promotes faster, more e󰀩cient service and
accurate repairs resulting in fewer call backs.

Before attempting to diagnose an operating fault code, run
a Heating Performance Test to determine if the heating
system is performing within 5% of the BTU input found on
the rating plate of the unit being tested. To conduct a heating
performance test, the BTU input to the unit must be calculated
(see Clocking a Gas Meter). Before clocking a gas meter,
contact your local utility to provide the caloric value (BTU
content) of the natural gas in the area.
It is also important to conrm the airow (CFM) is within the
temperature rise range (see Airow Data in spec sheet) and
external static pressure range (approximately 0.5” water
column). How-to instructions can be found in the service
manual under Checking External Static Pressure and
Checking Temperature Rise.