Troubleshooting - Honeywell 51370B Manal

TROUBLESHOOTING

LED Status
None (LED not on or
flashing)
One short flash every
four seconds
Alternates bright and
dim (Heartbeat)
Short flash once
every second
Short flash once
every two seconds
Two flashes, three
second pause
Three flashes, three
second pause
Four flashes, three
second pause
Five flashes, three
second pause
Six flashes‐one flash,
three second pause
(Soft lockout)
Control Status
Electrical power not
present.
Stand‐by mode,
Thermostat is
satisfied (no faults).
Thermostat calling
for heat (no fault).
Weak pilot signal on
last call for heat.
Idle remote
command off
Pressure switch not
working‐closed
position.
Pressure switch or
blower temperature
switch not working ‐
open position.
Excessive tank
temperature.
System must be
reset.
False pilot flame
present.
Failed to light pilot.
System auto resets
after 5 minutes.
Probable Cause
Control power switch in "OFF" position. Supply
voltage interrupted.
Temperature demand is satisfied (no call for heat).
Tank temperature below set point of thermostat.
1. Unstable pilot.
2. Pilot tube block or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection
at gas valve.
1. Control put in idle or Sabbath mode from
accessory module
1. Pressure switch tubing kinked or blocked.
2. Blocked pressure tap on switch.
3. Faulty pressure switch.
1. Vent blockage or improper vent configuration.
2. Pressure switch tubing kinked or blocked.
3. Blower not spinning up to speed.
4. Vent temperature too high
5. Faulty pressure switch or vent limit switch.
1. Excessive sediment
2. Hot water entering the tank from another
source in the potable loop.
3. Faulty gas valve.
1. Pilot valve stuck in open position.
1. Unstable pilot.
2. Pilot tube blocked or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection at gas valve.
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