Reznor R8HE Unit Installation Manual - Manual (Page 21)

21
3. Set the thermostat above room temperature and verify
the units operating sequence ( page 21 ).
NOTE: The over-temperature limit control should turn
off the gas valve within approximately four minutes
(exact time depends on the efficiency of the close-off
when blocking the return air). The circulating air and
combustion blowers should continue to run when the
over-temperature limit control switch opens.
4. Remove the close-off plate immediately after the over-
temperature limit control opens. If the unit operates
for more than four minutes with no return air, set the
thermostat below room temperature, shut off power to
the unit, and replace the over-temperature limit control.
Verifying Burner Operation
WARNING:
Uninsulated live components are exposed when
louvered control access panel is removed.
1. Remove the louvered control access panel and verify
there is power to the unit.
2. Set thermostat above room temperature and observe
the ignition sequence.
NOTE: The burner flame should carry over immediately
between all burners without lifting off, curling, or floating.
The flames should be blue, without yellow tips. Make
sure the flame is drawn into the center of the heat
exchanger tube. In a properly adjusted burner assembly,
the flame bends down and to the right at the end of the
heat exchanger tube. The end of the flame will be out
of sight around the bend.
3. After validating flame characteristics, set the thermostat
below room temperature and verify the burner flame
extinguishes completely.
Verifying System Cooling
(Single Stage Operation)
WARNING:
These units are shipped fully charged with
R-410A refrigerant and ready for installation.
When a system is installed according to these
instructions, no refrigerant charging is required.
If repairs make it necessary for evacuation and
charging, it should only be done by qualified,
trained personnel thoroughly familiar with this
equipment. Some local codes require licensed
installation/service personnel to service this type
of equipment. Under no circumstances should
the owner attempt to install and/or service this
equipment. Failure to comply with this warning
could result in property damage, personal injury,
or death.
CAUTION:
This unit uses R-410A refrigerant. DO NOT use
any other refrigerant in this unit. Use of another
refrigerant will damage the unit.
1. Set the thermostat’s system mode to COOL and the
fan mode to AUTO. Gradually lower the thermostat
temperature setpoint below room temperature and verify
the compressor, fan and indoor blower energize.
2. Feel the air being circulated by the indoor blower and
verify that it is cooler than ambient temperature. Listen for
any unusual noises. If unusual sounds occur, determine
the source of the noise and correct as necessary.
3. Allow the cooling system to operate for several minutes
and then set the temperature selector above room
temperature. Verify the fan and compressor cycle off
with the thermostat. NOTE: The blower will also stop
after a 60 second delay.
The system refrigerant charge can be checked and
adjusted through the service ports provided at the front
panel. Use only gauge lines which have a “Schrader”
depression device present to actuate the valve. Draw a
vacuum on gauge lines to remove air before attaching
them to the service ports on the unit. Refrigerant charging
must be done by qualified personnel familiar with safe
and environmentally responsible refrigerant handling
procedures.
OPERATING SEQUENCE
The operating sequences for the heating, cooling, and
fan modes are described below. Refer to the field and
unit wiring diagrams:
Figure 13 (page 37) , Figure 14
(page 38) , & Figure 15 (page 39) .
Heating Mode
1. On a call for 1st stage heat, the thermostat closes and
applies 24 VAC to terminal W1 on the control board.
2. Safety Circuit Proving - The control board verifies
continuity through the 24VAC limit control circuit. If the
high temperature limit switch, inducer limit, and flame
roll-out switch are closed and both the inducer hall
effect sensor and vent pressure switches are open, the
control board will then begin pressure switch proving. If
an open limit is detected, the control board will energize
the indoor blower motor and operate it continuously
while the limit switch circuit is open. All other system
functions will be inoperable until the limit circuit closes.
While the limit circuit is open, the control will display
Open Limit Switch Fault. See
Table 5 (page 25) .
3. The furnace control checks for continuity (24 VAC) across
the hall effect sensor and pressure switch. If either the
hall effect sensor or vent pressure switch is closed, the
heat mode sequence will not continue. If either remains
closed, the control will display a Pressure Switch Closed
with Inducer Off Fault until the fault condition clears.
4. Hall Effect Sensor and Pressure Switch Proving - The
control energizes the induced draft motor on High speed
and waits for the hall effect sensor and vent pressure
switch to close. If the hall effect sensor switch does