To Start The Furnace; To Shut Down The Furnace; Sequence Of Operation - Rheem 97MDV060 Series Installation Instructions Manual

COMMUNICATING FURNACE
This furnace is equipped with a direct ignition control.
Each time the room thermostat calls for heat, the igniter
lights the main burners directly. See the lighting
instructions on the furnace.

TO START THE FURNACE

1. Remove the burner compartment and blower control
access door.
2. IMPORTANT: Be sure that the manual gas control has
been in the "OFF" position for at least five minutes. Do
not attempt to manually light the main burners.
3. Turn off the furnace electrical power and set the room
thermostat to its lowest setting.
4. Turn the gas control to the "ON" position or move the
gas control lever to the "On" position.
5. Configure the dipswitches so that the furnace will op-
erate at 100% heat rate regardless of the heat de-
mand to "W1", "W2" or "V". This is done as follows:
For the single rate mode, when dipswitch SW10 is
"OFF" and SW11 is "ON", the furnace will operate in
the 100% heat mode with any legacy call for heat (first
stage, second stage or modulating). That is, a 24 VAC
signal on "W1" will cause the furnace to go through a
normal heating cycle with heating fire rate fixed at
100%. The voltage at the terminal labeled "V/W2" will
be ignored.
6. Replace the burner compartment control access door.
7. Turn on the furnace electrical power.
8. Set the room thermostat to a point above room
temperature to light the main burners.
9. The furnace control will go through a complete calibra-
tion sequence. See section titled "Sequence of Oper-
ation" for a description of this sequence.
10. After the calibration sequence is completed the fur-
nace will automatically fix the firing rate to 100%. Op-
erate the high gas heat for a minimum period of 15
minutes and adjust input rate (see section of this book
titled Adjusting Input Rate) and observe condensate
system for leaks. Correct leaks and set rate, shut
down furnace and repeat until no leaks in condensate
system can be detected.
11. Turn off the furnace electrical power and remove the
blower door.
12. Configure the dipswitches so that the furnace will op-
erate at 40% heat rate regardless of the heat demand
to "W1", "W2" or "V". This is done as follows:
For the single rate mode, when dipswitch SW10 is
"ON" and SW11 is "OFF", the furnace will operate in
the 40% heat mode with any legacy call for heat (first
stage, second stage or modulating). A legacy heat call
will cause the furnace to go through a normal heating
62
cycle with heating fire rate fixed at 40%. The voltage
at the terminal labeled "V/W2" will be ignored.
13. Replace the burner compartment control access door.
14. Turn on the furnace electrical power.
15. Set the room thermostat to a point above room
temperature to light the main burners.
16. The furnace control will go through a complete calibra-
tion sequence. See Section titled "Sequence of Op-
eration" for a description of this sequence.
17. After the calibration sequence is completed the fur-
nace will automatically set the firing rate to 40% (low).
Operate the low gas heat for a minimum period of 15
minutes and adjust input rate (see section of this book
titled Adjusting Input Rate) and observe condensate
system for leaks. Correct leaks and set rate, shut
down furnace and repeat until no leaks in condensate
system can be detected.

TO SHUT DOWN THE FURNACE

1. Set the room thermostat to its lowest setting and wait
for furnace to shut down.
2. Remove the burner compartment control access door.
3. Shut off the gas to the main burners by turning the
gas control to the "OFF" position.

SEQUENCE OF OPERATION

HONEYWELL CONTROLS Integrated Controls
with Direct Spark Ignition
CALIBRATION SEQUENCE:
The calibration sequence shall be performed prior to the
pre-purge under any of the following conditions:
1. The first gas heat call after cycling of main power (line
voltage),
2. Once every 100 heat calls or
3. The next heat attempt after any unexpected opening
of a pressure switch (low, middle or high) for more
than two seconds during any steady state heating op-
eration.
4. A failed pre-purge.
5. A failed calibration of the inducer on the previous igni-
tion attempt.