Troubleshooting; Before Troubleshooting; Check Control Module Fuses - Lochinvar Armor 150 - 500 Service Manual

3

Troubleshooting

Label all wires prior to disconnection
WARNING
when servicing controls. Wiring errors
can cause improper and dangerous
operation. Always disconnect power to
the water heater before servicing.
Failure to comply could result in severe
personal injury, death, or substantial
property damage.
Never jumper (bypass) any device
WARNING
except for momentary testing as
outlined in the Troubleshooting chart.
Severe personal injury, death, or
substantial property damage can result.

Before troubleshooting:

1. Have the following items:
a. Voltmeter that can check 120 VAC, 24 VAC, and
12 VDC.
b. Continuity checker.
c. Contact thermometer.
2. Check for 120 VAC (minimum 102 VAC to maximum
132 VAC) to water heater.
3. Make sure thermostat is calling for heat and contacts
(including appropriate zone controls) are closed. Check
for 24 VAC between thermostat wire nuts and ground.
4. Make sure all external limit controls are installed and
operating.
Check the following:
1. Wire connectors to control module are securely plugged
in at the module and originating control.
2. Gas pressures:
• Maximum: 14 inches w.c. (natural and LP) with no
flow (lockup) or with water heater on
• Minimum: 4 inches w.c. (natural), 8 inches w.c. (LP)
with gas flowing (verify during water heater startup)

Check control module fuses

ALWAYS check control module fuses before
NOTICE
replacing control module or any major
components (blower, etc.). If one of these
fuses is blown, it can prevent the control
module
operating.
1. Turn OFF power to the water heater at the external line
switch.
2. Remove top access cover.
3. Remove the control module cover.
4. Inspect fuses F2, F3, F4, and F5, see FIG 3-1 below.
Figure 3-1 Control Module Fuses
F4 - 3.15 AMP FUSE
GAS VALVE
F5 - 5 AMP FUSE
PUMPS
F2 - 3.15 AMP FUSE
24V SUPPLY
5. The water heater is shipped with three (3) spare fuses in a
plastic bag attached to the control module cover.
6. If necessary, replace open fuse (F3 is 1.25 amps, F2 and F4
are 3.15 amps, and F5 is 5 amps).
Note: Fuses F2 - F5 are all slow blow fuses.
Do not jumper fuse or replace with any fuse
WARNING
except as specified. Failure to comply could
result in severe personal injury, death, or
substantial property damage.
7. Install control module cover and top access cover after fuse
inspection.
8. Restore power to the water heater at the external line switch
and verify water heater operation (Section 10 - Start-up in
the Armor Water Heater Installation and Operation
Manual) after completing water heater service.
Service Manual
or other components
F3 - 1.25 AMP FUSE
MAIN BOARD
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