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H2O BOILER
HC SERIES IOM Manual
4.2 Troubleshooting
Fault
Cause
Corrective Action
Blower does not start
Power not supplied to the unit.
Safety loop open.
None of the above
Ensure power switch is on.
Check both fuses on the power and the supply
sides.
Ensure BMS (if connected) calls for heat.
Ensure high temperature limit switch is closed.
Ensure operating temperature switch is closed.
Ensure low gas pressure switch are closed.
See burner catalogue for burner controller
trouble shooting.
Unit does not start
Blower does not run.
Air pressure switch installed
on the housing is open.
Gas pressure switch is open.
No ignition.
See above
Adjust switch.
Replace switch (if defective).
Adjust the switch.
Replace switch (if defective).
See burner catalogue for burner controller
trouble shooting
Pilot flame failure
Pilot gas valve not opened
No ignition
Check the electrical connections to ensure they
are all securely connected (see the schematic
wiring diagram for terminals).
Check the two safety shut off valves. Replace if
defective.
Check the electrical connections to ensure they
are all securely connected (see burner catalogue)
for terminals.
Measure gas pressure and air pressure in the pilot
burner at the available test port. Ensure it is within
the specified 2”-5” wc. If pressure is not available
check both safety shut off valves and the pressure
regulator. Replace any defective component, if
necessary.
Main flame failure
Main gas valve not opened.
Insufficient gas pressure
Check the electrical connections to ensure they
are all securely connected.
Check the two, safety shut off valves. Replace
if defective.
Check gas pressure at the inlet test port of the
first safety shut off valve. It should be within
the specified 7-14” wc range. Adjust the
pressure regulator to obtain the required
pressure. If problem persists, replace the valve.
Repeat process for the second safety shut off
valve.
D-VAC Sales Inc. Email: dmann@dvachvac.com Tel: (516) 256-3131 www.dvachvac.com
