45
Check Gas Supply Pressure
1. Slowly turn on main gas shut-off valve.
2. Read the gas supply pressure from the manome-
ter;minimum supplypressure fornatural gasis 4.0
in. WC, recommended supply is 7.0 in. WC, mini-
mum supply pressure for propane gas is 4.0 in.
WC, recommended supply is 11.0in. WC (dynam-
ic readings, full fire input).
3. If the gas pressure is greater than 14.0 in. WC,
turn off the main gas shut-off valve.
Start-Up
1. Turn power on.
2. Turnon the heater, wait approximately 15 seconds
after the blower starts, and the igniter should start
to glow (observable through the observation port
located at the front, bottom of the heater). Look
into the sight glass located at the bottom of the
front panel to check igniter operation. Gas valve
should open in 45-60 seconds.
3. The heater ignites at 50% of full rate (as indicated
on the LCD display of the temperature control
located in the upper right of the front panel).
4. If the burner fails to light on the first trial, it will go
into lockout with the optional single-try ignition
module.If theheater isequipped withthe standard
three-try ignition module, it will try for ignition up to
three times before going into lockout.
5. Wait until the controller indicates 100% on the fir-
ing rate display s creen (approximately 30
seconds).
Initial Start-up

Required tools

• (1) 12-0-12 (24” scale) U-tube manometer
• (2) 6-0-6 (12” scale) U-tube manometer
• Screwdrivers (assorted sizes and shapes)
• (1) Crescent wrench (8” or 10”)
• (1) Multi-meter
• (1) Amp probe
(Metric Allen wrenches will be required for servicing
the gas valve, but not during start-up)
Preparation
Check Power Supply
With multi-meter at incoming power, check voltage
between:
Hot - Common (≈120 VAC)
Hot - Ground (≈120 VAC)
Common - Ground (< 1 VAC)
Attach Manometers to Measure Pressures
1. Turn off main gas valve.
2. Attach (1) 12” scale manometer to an upstream
bleedle valve on the gas supply pipe to the heater
(Measure point “A” in Fig. 52).
3. Attach (1) 24” scale manometer to the manifold
pressure tap located on the elbow downstream of
the valve (Measure point “D” in Fig. 52).
4. Attach (1) 12” scale manometer near the fan-prov-
ing switch. Pull black cap from air pressure switch
tee and connect the manometer. NOTE: Retain
caps for reinstallation later.
WARNING: If Common - Ground is > 1 VAC,
STOP: Contact electrician to correct ground failure.
Failure to do this m ay burn out 120V-24V
transformer, or may cause other safety control
damage or failure.
GAS
TO BURNER
AB
CD
Fig. 52: Gas Pressure Measurement Locations
NOTE: The values in TablesV, W and X represent
the conditions when the heater is at full firing rate at
sea level.
NOTE: Digital manometers are not recommended.
WARNING: Do not turn on gas at this time.