GAS PRESSURE CHECKS
17
WARNING
Fire aand EExplosion H
Hazard
■
Do not disassemble the gas control valve.
■
Do not attempt to replace any components on the gas
control valve.
■
The gas control valve must be replaced if any physical
damage occurs to the control valve assembly.
■
Failure to follow this warning will result in fire or
explosions, leading to injury or death to humans and
livestock, and building damage.
OUTL
TA
INLET PRESSURE
TAP SCREW
INLET PRESSURE TAP
LOW PRESSURE GAUGE
LOW PRESSURE GAUGE
INTERNAL PRESSURE
REGULATOR
OUTLET PRESSURE TAP
ON
OFF
O
5
10
15
20
25
30
35
O
5
10
15
20
25
30
35
INLET PRESSURE TAP
OUTLET PRESSURE TAP
ATTENTION
■
The following explains a typical procedure to be followed
in checking gas pressures.
■
The gas pressures will vary depending upon model
number and fuel type.
■
Consult the dataplate on the heater or page 4 in this
manual for specific pressures to be used in conjunction
with this procedure.
■
Gas pressure measured at the inlet to the gas valve is
Inlet Pressure and gas pressure measured at the outlet
of the gas valve is burner Manifold Pressure.
A. Preparation
1. Obtain two pressure gauges capable of reading up to
35 in. W.C.
2. Disconnect the heater from the electrical supply and
close the fuel supply valve to the heater inlet.
3. Open the control box.
4. Brush or blow off any dust and dirt on or in the
vicinity of the gas control valve.
B. Gauge IInstallation
1. Remove the inlet and outlet pressure tap plugs. See
Fig. 13.
2. Securely connect a pressure gauge to each pressure
tap port.
3. Open the fuel supply valves to the heater and
reconnect the heater electrical supply.
4. Start the heater.
C. Reading PPressures
1. With the heater operating, the pressure gauges
should read the pressures specified on the dataplate.
2. Do the readings at the inlet and outlet pressure
gauges agree with that specified on the dataplate? If
so, then no further checking or adjustment is
required. Proceed to Section D.
3. If the inlet pressures do not agree with that specified
on the dataplate, then the building system regulator
controlling gas pressure to the heaters requires
adjustment.
4. If the inlet pressures are correct and the burner
manifold pressure does not agree with that specified
on the dataplate, then the gas control valve’s internal
pressure regulator requires adjustment. See Fig. 14
for regulator location.
D. Completion
1. Once inlet and burner manifold pressures have been
confirmed and/or properly set, close the fuel supply
valve to the heater and allow the heater to burn off
any gas remaining in the gas supply line.
2. Disconnect the heater from its electrical supply.
3. Remove the gauges.
4. Reinstall the pressure tap plugs and tighten securely.
FIG. 13
FIG. 14
