Publicidad
Idiomas disponibles
Idiomas disponibles
TROUBLESHOOTING YOUR FURNACE
For qualified service technicians.
ISSUE
1.
Pilot will not stay lit after
following lighting instructions.
2.
No gas to the main burner
3.
Furnace operates but turns off
before room temperature is
attained.
4.
Furnace not producing
sufficient heat..
5.
Furnace operates but
will not shut off when room
temperature is attained.
6.
Pilot outage.
40
POSSIBLE CAUSE(S)
a.
Generator producing
insufficient millivolts.
b.
Loose or dirty generator
connections at gas valve.
c.
Generator defective.
d.
Grounded thermostat wire.
e.
Defective gas valve.
a.
Gas valve not turned to the "ON"
position after lighting pilot.
b.
Thermostat not tuned to a
position calling for heat.
c.
Improper wired or
broken thermostat wires.
Defective thermostat.
d.
Vent safety switch tripped.
e.
Pilot generator may not be
generating sufficient millivolts
to open valve.
f.
Defective valve.
g.
Plugged furnace orifice.
a.
Thermostat location.
b.
Defective thermostat.
a.
Furnace may be too small for
space being heated.
b.
Furnace not burning at full rate.
a.
Thermostat wiring defective.
b.
Thermostat location.
c.
Defective thermostat.
d.
Valve stuck open.
a.
Pilot flame may be low or
blowing (high).
b.
Drafts or drafty areas.
CORRECTIVE ACTION
a.
Check pilot flame. It must impinge on the generator.
b.
Clean and/or tighten generator connections at valve.
c.
Check generator with millivolt meter. Take reading
at generator terminals of the valve with the valve
placed in "Pilot" position. Disconnect the thermostat
wires. The millivolt reading should be 450 millivolts
or more.
d.
Remove thermostat wires from valve terminals. If
pilot now stays lit, trace thermostat wiring circuit for
a ground. May be grounded to furnace, gas supply,
nails or staples.
e.
Replace gas valve after above is verified.
a.
Turn gas valve knob to the "ON."
b.
Set thermostat to a position calling for heat.
c.
Check connections at valve terminals. If valve operates,
check thermostat wires.
d.
Check and reset.
e.
See 1a and 1c above.
f.
Replace gas valve after above is verified.
g.
Check-clean or replace.
a.
Check thermostat location. It should not be in the path
of warm air discharge from furnace, near a lamp or
above a T.V. or stereo unit.
b.
Check thermostat calibration or replace.
a.
Check heat sizing calculations.
b.
Check for low gas pressure at gas valve. It should be 4
inches water column for natural gas; 10-inches water
column for propane gas. Check for blocked burner orifices.
a.
Thermostat lead wires may be shorted together,
caused by a nail or staple. Check by removing
thermostat leads from valve terminals.
b.
Check thermostat location. If on an outside wall, or
there is a hole in the wall behind the thermostat,
cold air may be coming in contact with the thermostat.
c.
Check thermostat calibration; verify thermostat
temperature reading; or replace.
d.
Replace valve.
a.
Adjust pilot flame. Pilot orifice may be plugged
(check for spider webs or other material).
b.
Check for doorway and high movement areas.
Publicidad
