18-CD29D1-11
37
Installer’s Guide
ABNORMAL CONDITIONS
1. EXCESSIVE COMBUSTION PRESSURE (WIND IN
EXCESS OF 40 M.P.H.) VENT OR FLUE BLOCKAGE
If pressure against induced draft blower outlet becomes
excessive, the pressure switch will open and shut off
the gas valve until acceptable combustion pressure is
again available.
2. LOSS OF FLAME
If loss of flame occurs during a heating cycle, or flame
is not present at the sensor, the flame control module
will close the gas valve. The flame control module will
then recycle the ignition sequence, then if ignition is
not achieved, it will shut off the gas valve and lock out
the system.
3. POWER FAILURE
If there is a power failure during a heating cycle, the
system will restart the ignition sequence automatically
when power is restored if the thermostat still calls for
heat.
4. GAS SUPPLY FAILURE
If loss of flame occurs during a heating cycle, the sys-
tem integrated control module will recycle the ignition
sequence, then if ignition is not achieved, the integrat-
ed control module will shut off the gas valve and lock
out the system.
5. INDUCED DRAFT BLOWER FAILURE
If pressure is not sensed by the pressure switch, the
contacts will remain open and not allow the gas valve
to open, therefore the unit will not start. If failure oc-
curs during a running cycle, the pressure switch con-
tacts will open and the gas valve will close to shut the
unit down.
6. CONDENSATE DRAIN BLOCKAGE
If the condensate drain is blocked, either by debris, im-
proper draining, or by freezing condensate, the pres-
sure switch will receive a signal warning of the accu-
mulation of condensate in the heat exchanger assem-
bly. The pressure switch contacts will open and remain
open, not allowing unit operation. The unit will not op-
erate until the condensate drain has been cleared, and
the condensate flows freely.
7. RESET AFTER LOCKOUT
When the integrated control module has shut the sys-
tem down and gone into lockout, the system must be
manually reset before the unit will restart. To reset,
turn the system power off, then on, then off and then
on again within 30 seconds. This may be done at the
unit’s power source or at the thermostat.
The system
will not reset unless the procedure off-on-off-on is com-
pleted within 30 seconds.
8. RESET AFTER BURNER BOX LIMIT SHUTDOWN
If the furnace shuts down, one thing that can be
checked is the burner box temperature limit switch.
It is located on the bottom of the burner box. The
vent and combustion air inlet terminations should be
checked for blockage. If blockage exists, clear the prob-
lem and then the reset button may be depressed.
If
there is no blockage of the terminations, the limit
switch must be reset by a qualified servicer.
Carbon monoxide, fire or smoke can cause serious bodily in-
jury, death, and/or property damage.
A variety of potential sources of carbon monoxide can be
found in a building or dwelling such as gas-fired clothes
dryers, gas cooking stoves, water heaters, furnaces and
fireplaces. The U.S. Consumer Product Safety Commis-
sion recommends that users of gas-burning appliances in-
stall carbon monoxide detectors as well as fire and smoke
detectors per the manufacturers installation instructions to
help alert dwelling occupants of the presence of fire, smoke
or unsafe levels of carbon monoxide. These devises should
be listed by Underwriters Laboratories, Inc.
Standards for
Single and Multiple Station Carbon Monoxide Alarms, UL
2034
or CSA International Standard,
Residential Carbon
Monoxide Alarming Devices,
CSA 6.19
NOTE:
The manufacturer of your furnace does not test any detec-
tors and makes no representations regarding any brand or
type of detector.
