Operating instructions

Part number 550-141-887/0800
36
AHE Series 4 Direct Vent Wall-Mounted Boilers — Boiler Manual
Troubleshooting — charts continued 12d
Electrical shock hazard — Wherever you see ▲TURN OFF POWER▲, follow the instructions. Failure to follow
instructions could result in severe personl injury, death or substantial property damage.
CHART 2 — TSTAT CIRC & POWER lights flashing
• Remove CIRCULATOR plug ( Figure 29, page 34, Item
4
) from plug receptacle of control module.
• Place voltmeter leads across the right-side 120 VAC N
and 120 VAC H pins of the CIRCULATOR receptacle.
Does the voltmeter indicate 120 VAC?
No Yes
• Replace control
module.
• Retest.
• Replace circulator
harness.
• Retest.
• Reconnect circulator harness to control module.
• Attempt to get the circulator started by giving it a sharp
rap on the end of the circulator motor (to release a
possibly locked impeller).
• If the circulator begins to operate, allow it to operate for a
few minutes to see if the problem clears.
• If problem persists, replace the circulator.
• Retest.
No Yes
Is boiler circulator operating?
Did you find and correct a voltage across the two external thermostat circuit wires?
• Test wire continuity of
circulator wire harness.
Is harness ok?
No Yes
NoYes
• Boiler should now operate per the normal sequence of
operation shown in Figure 17, page 22, if wiring was
corrected.
• Check the boiler internal return pipe where it enters the
boiler sections. The TSTAT CIRC and POWER lights will
flash as long as the return water temperature is less than
130 ˚F.
• Wait up to 20 minutes to give the boiler and system a
chance to respond.
Does problem persist?
No Yes
• Boiler may now be operating
normally. Verify against
Figure 17, page 22, sequence
of operation.
• If boiler appears not to be heating, troubleshoot boiler per
CHART 8 (no heat problems).
• If boiler is heating, but the temperature at the return pipe
does not increase above 130 ˚F, there may be an
incorrectly-piped external circulator forcing water through
the boiler. Check external piping and correct.
• Check for stray voltage on the incoming thermostat wires.
Disconnect the two external wires connected to the boiler
thermostat wires.
• Connect a voltmeter across the two incoming wires. Close
each thermostat, zone valve and relay in the external circuit
one at a time and check the voltmeter reading across the
wires. There should NEVER be a voltage reading. If a voltage
does occur under any condition, check and correct the
external wiring. (This is a common problem when using 3-wire
zone valves.)
• Once the external thermostat circuit wiring is checked and
corrected if necessary, reconnect the external thermostat
circuit wires to the boiler thermostat wires and allow the boiler
to cycle.