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10. Replace the blower access door.
11. Restore electrical power to the furnace.
Routine cleaning the interior of the recovery coil
should not be necessary. If evidence develops indicat-
ing that a cleaning is necessary, it should be done by
a trained and qualifi ed service technician. Evidence
may include large amounts of dirt or debris building
up in the condensate drain line.
The burner area should be inspected and cleaned
periodically. Be careful when cleaning around the
burner area. The hot surface igniter is fragile and
will break easily. Do not touch the hot surface ig-
niter or fl ame rod.
WARNING
NEVER ATTEMPT TO CLEAN THE BURNER
AREA WHILE THE BURNERS ARE OPERAT-
ING. DOING SO MAY RESULT IN EXPLOSION
OR FIRE RESULTING IN SEVERE PERSON-
AL INJURY OR DEATH.
ALWAYS DISCONNECT THE ELECTRICAL
SUPPLY TO THE FURNACE BEFORE RE-
MOVING THE BURNER COMPARTMENT AC-
CESS DOOR.
CAUTION
The furnace gas train is designed to operate
as a sealed unit. Be sure that the burner com-
partment access door is properly in place
before attempting to restart the furnace.
The furnace achieves its high effi ciency in three
general areas. First, there is no wasteful standing
pilot. The furnace consumes no gas in between
cycles. Secondly, the furnace is designed to allow
very small amounts of excess air in the combus-
tion process. Older furnaces had heat exchangers
which were commonly 40% larger than necessary
for complete combustion. While this prevented the
creation of carbon monoxide, the heated excess air
was expelled up the chimney where it could not ben-
efi t the interior of the home. Special safety controls
now prevent the formation of carbon monoxide.
The third general area is the recovery of the latent
heat contained in the fl ue gas, which is comprised of
water vapor and carbon dioxide. By condensing the
fl ue gas in the furnace recovery coil, heat that would
otherwise be wasted to the outdoors, is captured
and redirected into the duct system where it contrib-
utes to home comfort. Each pound of condensation
formed releases approximately 970 BTUs. Your fur-
nace may condense up to ½ gallon (5 pounds) of
water per hour if running continuously.
This condensation must be properly disposed into
a sump or drainage system. The condensate lines
must remain clear and free fl owing. Do not allow
plastic drain lines to become pinched or kinked. A
blocked drain line can cause the furnace to operate
erratically, or not at all.
IMPORTANT:
Your furnace should be cleaned
and inspected annually by a trained and quali-
fi ed service technician. Your service technician
has the knowledge and test equipment to deter-
mine the condition of your furnace.
95V SEQUENCE OF OPERATION
1. Room temperature drops causing the room
thermostat call for fi rst stage heat by connecting
“W1” to “R”. The control verifi es the limit switch
is closed and both the low and high pressure
switches are open. The control energizes the
induce draft motor on high speed and waits for
the low pressure switch to close. The inducer
remains on high speed and begins a 15 second
pre-purge period. The high pressure switch is
ignored. If the low pressure switch does not
close within 60 seconds, the control will fl ash “2”
on the Status LED, and de-energize the inducer
for 60 minutes.
2. When the 15 second pre-purge time has
elapsed, the control energizes the *HSI output
for a 5 second warm-up period (10 seconds on
retries). The control energizes the low main gas
valve. 4 seconds after the gas is energized, the
control de-energized the *HSI output and leaves
the gas energized another 1 second for fl ame
proving. If fl ame is present at the end of the trial
for ignition time, the control leaves the gas valve
energized, inducer on high speed, and begins
heat blower on delay. The control always ignites
on high inducer/low gas and ignores second
stage call for heat until low heat is established
for 15 seconds.
(*HSI= Hot Surface Ignition)
3. Blower on delay time begins when the gas
valve is energized. The control provides the
ECM (Electronically Commutated Motor) low
heat speed signal when fl ame is proven, and
starts a 30 second soft start (slowly ramp up)
blower delay before full capacity blower level.
