Care & Maintenance - Procom GHBVN50 Manual

A natural to LP/propane gas changeover kit is required to convert unit. Refer to the installation instructions supplied with
the changeover kit for conversion procedure. If unit is installed at an altitude greater than 7500 feet (1372m), unit must
be derated by four percent for each additional 1000 feet (305m) above 7500 feet or as specified by local authority having
jurisdiction.
The combustion air inducer proving switch is factory set. No adjustment is necessary.
Gas Flow
To check for proper gas flow to the combustion chamber, determine the Btu input from the appliance rating plate. Divide
this input rating by the Btu per cubic feet of available gas. Result is the required number of cubic feet per hour. Determine
the flow of gas through the gas meter for two minutes and multiply by 30 to get the hourly flow of gas.
Gas Pressure Adjustment
1. Check gas line pressure with unit firing at maximum rate. A minimum of 7" (178mm) w.c. for natural gas or 10.4"
(264mm) w.c. for LP/propane gas should be maintained for proper unit operation.
2. After line pressure has been checked and adjusted, check regulator pressure. Correct manifold pressure is shown on
the unit rating plate. See figures 9 and 10 for gas pressure adjustment screw location. A natural gas to LP/propane gas
changeover kit is required to convert unit. Refer to installation instructions provided with changeover kit for conversion
procedure.
Limit Control
The limit control switch is factory set and not field adjustable.
Louver Vane Adjustment
Rotate louver vanes to direct airflow upward, downward, straight, or any combination of these directions. When unit is
installed in an inverted position, louvers may be positioned in the same manner.
Combustion Air Pressure Switch
This pressure switch checks for proper combustion air inducer operation before allowing an ignition trial. The switch is
factory set and no field adjustment is necessary.
Flame Rollout Switch
The flame rollout switch(es) are located on the burner box top, behind the ignition control board. This normally closed
switch opens on a temperature rise. Check for adequate combustion air before manually resetting switch.
CARE AND MAINTENANCE
CAUTION: Turn off gas and electrical power to unit before performing any maintenance or service operations on this unit.
Remember to follow lighting instructions when putting unit back into operation after service or maintenance.
BURNER
Periodically examine burner flames for proper appearance during the heating season. Before each heating season examine the
burners for any deposits or blockage that may have occurred. Clean burners as follows:
a. Turn off both electrical and gas supplies to unit.
b. Disconnect gas supply piping, high tension and sensor leads. Remove gas manifold. Remove burner tray.
c. Clean burners as necessary. Make sure that burner heads line up properly to ensure flame crossover. Check spark gap on
electrode and adjust if required. The gap should be between 0.110" and 0.140" (3mm to 4mm). The gap may be checked
with appropriately sized twist drills or feeler gauges.
d. Reinstall burner tray, gas manifold, high tension and sensor leads. Reconnect gas supply piping.
e. Restore electrical power and gas supply. Follow lighting instructions to light unit. Check burner flame.
FLUE PASSAGEWAY AND FLUE BOX
The flue passages and flue box should be inspected and cleaned prior to each heating season. The sequence of operation
should be as follows:
1. Turn off both electrical and gas supply to unit.
2. Disconnect combustion air inducer wiring.
3. Remove screws securing flue box to unit. Remove flue box. If necessary, remove inducer assembly from flue box. Clean
flue box with wire brush.
4. Remove turbulator retention bracket and turbulators. Clean turbulators with wire brush.
5. Remove burners as described in section "Burners" section.
6. Clean tubes with a wire brush.
7. Reassemble unit. The combustion air and flue box gaskets should also be replaced during reassembly.
8. Restore electrical power and gas supply. Follow lighting instructions to light unit. Check operation of unit.
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