Heating Mode - Goodman MVC8 Installation Instructions Manual

1 Flash
Red
Communications
LED
2 Flashes
1 Steady
Flash
Green Receive
LED
Rapid
Flashing
On Solid
H M
EATING ODE
The normal operational sequence in heating mode is as fol-
lows:
•
R and W1 (or R and W1/W2) thermostat contacts close,
initiating a call for heat.
•
Integrated control module performs safety circuit checks.
•
Induced draft blower is energized on high speed for a 15-
second prepurge. Humidifier terminal is energized with
induced draft blower.
•
Induced draft blower steps to low speed following
prepurge. Low stage pressure switch contacts are
closed.
•
Igniter warm up begins upon step to low speed and
presence of closed low stage pressure switch contacts.
LED Description
Off Normal condition
Communications
Failure
Out-of-box reset
Off •Nopower
•Communications
error
No network
found
Normal network
traffc
Data 1/ Data 2
miss-wire
Possible Cause
None None
Communications •Depress Learn Button
Failure
•Verify that bus BIAS and
TERM dipswitches are in
the ON position.
•Control power up None
•Learn button depressed
•No power to furnace •Check fuses and circuit
breakers; replace/reset
•Open fuse
•Replace blown fuse
•Communications error
•Check for shorts in low
voltage wiring in furnace/
system
•Reset network by
depressing learn button
•Check data 1/ data 2
voltages
•Broken/ disconnected •Check communications
data wire(s) wiring (data 1/ data 2
wires)
•Furnace is installed
as a legacy/ traditional •Check wire connections
system at terminal block
•Verify furnace installation
type (legacy/ traditional
or communicating) Check
data 1/ data 2 voltages
Control is "talking" on None
network as expected
•Data 1 and data 2 wires •Check communications
reversed at furnace, wiring (data 1/ data 2
thermostat, or CT™ wires)
compatible outdoor AC/
•Check wire connections
HP
at terminal block
•Short between data 1
•Check data 1/ data 2
and data 2 wires
voltages
•Short between data 1
or data 2 wires and R
(24VAC) or C (24VAC
common)
•
Gas valve opens at end of igniter warm up period, delivering
gas to burners and establishing flame.
•
Integrated control module monitors flame presence. Gas
valve will remain open only if flame is detected.
•
If the thermostat call is for low heat, gas valve and induced
draft blower will continue on low stage. If the call is for
high heat, the gas valve and induced draft blower will
change to high stage.
•
Circulator blower is energized on heat speed following a
thirty (30) second blower on delay. The circulator blower
requires thirty seconds to ramp up to full speed.
Electronic air cleaner terminal is energized with circulator
blower.
•
Furnace is now operating on the specified stage called
for by the two-stage thermostat.
35
Corrective Action
None
•Depress once quickly for
a power-up reset
•Depress and hold for 2
seconds for an out-of-box
reset
None
•Turn power OFF prior to
repair
•Turn power OFF prior to
repair
•Verify wires at terminal
blocks are securely
twisted together prior to
inserting into terminal
block
•Verify data1 and data
voltages as described
above
None
•Turn power OFF prior to
repair
•Verify wires at terminal
blocks are securely
twisted together prior to
inserting into terminal
block
•Verify data1 and data
voltages as described
above
Comments