20
POSSIBLE CAUSE
This indicates that the main
control board has failed one or
more of its internal diagnostic
self-tests.
REMEDY
Press red reset button on the
display board to reset the con-
trol. If this error occurs repeat-
edly, replace the main control
board.
CONTROL HEALTH
Control Health LED Flashing
POSSIBLE CAUSE
1. Combustion air blockage.
2. Blower not operating:
a. Blower wiring
b. Blower motor
3. Defective air switch
4. One of the gas valve wires-
may be disconnected dur-
ing ignition sequence.
5. Poly hose between the
blower and air pressure
switch is blocked or discon-
nected.
REMEDY
1. Check intake and exhaust
piping for obstructions.
2a. Repair wiring.
2b. Replace blower motor.
3. Replace air switch.
4. Check wires to Gas valve.
Reseat wires into harness.
5. Remove or correct block-
age connect hose to blow-
er or air pressure switch.
COMBUSTION AIR BLOCKAGE
Pressure Switch LED Flashing
POSSIBLE CAUSE
1. Temp probe wiring open.
2. Defective probe.
3. No water in tank or tank in
freezing conditions.
4. Water level in tank is too low
- probe in steam.
5. Probe wiring shorted.
REMEDY
1. Repair wiring.
2. Replace probe.
3. Control is recording an “out
of bounds” condition. Turn on
water supply; remove tank
from freezing conditions.
4. Control is recording an “out
of bounds” condition. Fill
tank.
5. Replace probe.
TEMPERATURE PROBE FAULT
Water Temp LED Flashing
NOTE:
If the temperature probe housing fractures and allows water into
the sensor section of the probe, this may affect the temperature
display on the display pnael. If the display is showing highly
inconsistent temperature readings, this is an indication the
temperature probe is defective due to water contamination.
Replace probe.
LINE
K1
COMB
BLOWER
K5
IGNITER
ELEMENT
24
VAC
ECO/VENT
SWITCH
SWITCH
PRESSURE
GAS
VALVE
RLY 1
GAS
VALVE
RLY 2
GAS
VALVE
CONTROL
HEALTH
WATER
TEMPERATURE
K1
K5
K3
K4
K4K3
CONTROL
ELECTRONICS
LINE
K1
COMB
BLOWER
K5
IGNITER
ELEMENT
24
VAC
ECO/VENT
SWITCH
SWITCH
PRESSURE
GAS
VALVE
RLY 1
GAS
VALVE
RLY 2
GAS
VALVE
CONTROL
HEALTH
WATER
TEMPERATURE
K1
K5
K3
K4
K4K3
CONTROL
ELECTRONICS
LINE
K1
COMB
BLOWER
K5
IGNITER
ELEMENT
24
VAC
ECO/VENT
SWITCH
SWITCH
PRESSURE
GAS
VALVE
RLY 1
GAS
VALVE
RLY 2
GAS
VALVE
CONTROL
HEALTH
WATER
TEMPERATURE
K1
K5
K3
K4
K4K3
CONTROL
ELECTRONICS