John Wood Commercial - 300-400K BTU - Manual (Page 59)

59
fault and alert messages (cont)
Call the technical support phone number listed on the back cover for further technical assistance or to locate a qualified service agent
in your area.
possible causes - check/repair displayed fault/alert message
• The control system has detected the blower Prover Switch
contacts are closed when they should be open at the beginning of
a heating cycle - see the Sequence Of Operation on page 59.
• Pinched/shorted blower Prover Switch wiring - see Figure 3 on
page 8 for switch location.
• Jumper wire connected to the blower Prover Switch - remove
jumper wire. Jumper wires must never be used, read all Warnings
on page 57.
• Excessive wind outdoors pressurizing the vent system piping.
• Excessive negative air pressure in the installed space.
CHANGE BACK ADVANCED
Blower Prover Failure
Fault occurred 2 mins ago
The blower prover switch is
closed out of sequence.
Call a service professional:
Your Company Name Here
(press [DOWN] for more....)
• The control system has detected the blower Prover Switch
contacts are remaining open after the control system has
energized the Combustion blower - see the Sequence Of
Operation on page 59.
• Loose or open wiring to the blower Prover Switch - see Figure 3 on
page 8 for switch location.
• blower Prover Switch air sensing tube disconnected, kinked, filed
with condensate, damaged or leaking - repair or replace tube.
• Combustion blower is not running when energized.
• Loose or open wiring to Combustion blower.
• Loose, open, incorrect wiring to the VFD on AHCg3 130T 400
models - see Figure 3 on page 8 and the wiring diagram on page 65.
CHANGE BACK ADVANCED
Blower Prover Open
Fault occurred 2 mins ago
The blower prover switch remains
open after the blower has been
energized.
Call a service professional:
Your Company Name Here
(press [DOWN] for more....)
• The control system has detected the blocked Intake Air Switch
contacts are open.
• Loose or open wiring to the blocked Intake Air Switch - see Figure
3 on page 8 for switch location.
• Excessive equivalent pipe length, exceeded the maximum number
of 90° elbows or wrong pipe size used in the intake air piping
system - see Venting requirements on page 21.
• balance plate and/or intake air screen was not removed prior to
connecting the intake air piping to the water heater and is clogged/
blocked with debris - see Figure 17 on page 23.
• Excessive negative air pressure in the installed space.
CHANGE BACK ADVANCED
Blocked Air Intake
Fault occurred 2 mins ago
The combustion air intake is
restricted.
Call a service professional:
Your Company Name Here
(press [DOWN] for more....)
• The control system has detected the ECO (energy cut out) Switch
contacts are open.
• The ECO switch is a normally closed switch that opens on a
temperature rise to prevent excessive water temperature in the
storage tank. The ECO switch is inside the upper Temperature
Probe (two red wires) - see Figure 3 on page 8 for upper Probe
location.
• Loose or open wiring to the ECO switch in the upper Temperature
Probe - two red wires.
• Improper water system piping and/or excessively high return
(recirculation) loop water temperature - see the Water Piping
Diagrams beginning on page 67.
CHANGE BACK ADVANCED
Energy Cut Out (ECO)
Fault occurred 2 mins ago
Tank temperature is excessive.
The water heater has been
disabled.
Call a service professional:
Your Company Name Here
(press [DOWN] for more....)
• The control system has not detected any voltage from the powered
anode rods - see Figure 3 on page 8 for location.
• No water in the storage tank.
• Loose or open wiring connections to the powered anode rods - see
Figure 3 on page 8 for location.
• Powered anode rod wiring shorted to ground.
• The water heater is not properly grounded - see Power Supply
Connections on page 38.
• Loose or open ground wires.
• Top fitting (3/4 inch bushing) of the powered anode rods were
saturated with water during installation - with power to the water
heater turned off, carefully remove anode rods and dry out
bushing(s).
CHANGE BACK ADVANCED
No Anode Voltage
Alert:
Alert occurred 2 mins ago
No voltage detected from
Powered Anode(s).
Call a service professional:
Your Company Name Here
(press [DOWN] for more....)