39
UH
Series
13
Remove the pressure gauge tube and the 1/8 inch NPT hose connector.
14
Replace the inlet pressure tap plug on the gas control valve.
15
Leak check the re-installed pressure tap plug using a soap solution or equivalent method
as described in ANSI Z223.1 (NFPA 54).
Figure 3.15
•
Gas Valve Shown in ON Position
Verify Manifold Pressure
Before starting up the unit, smell all around the unit heater for gas. Be sure to smell next to the
floor because some gas is heavier than air and will settle on the floor.
When turning the gas shut off valve, only use your hand. Never use tools to turn the knobs, as it
may damage the valve resulting in a fire or explosion. If the knob is stuck, do not try to repair it,
contact a qualified service technician or your local gas company.
To verify the proper manifold pressure, follow the following steps:
1
Turn off the gas valve with the switch located on the valve body (see Figure 3.15).
2
Remove the manifold pressure tap plug on the gas control valve(see Figure 3.15).
3
Connect the pressure gauge tube and manometer.
4
Turn on the gas valve with the switch located on the valve body.
5
Turn on the electrical power to the unit heater.
6
To light the main burners, set the room thermostat to a point above room temperature.
NOTE:
This unit heater is equipped with an ignition device, which automatically lights the
burner. This unit heater cannot be lighted manually. Do not try to light the burner by hand.
Verify manifold pressure:
7
After the unit has successfully ignited, wait five minutes prior to taking any readings. The
unit heater must be in a steady state of operation prior to taking a manifold pressure reading.
3.0
Installation
•
Verifying Manifold Pressure
Manifold Pressure
Adjustment Screw
(under cap)
Inlet
Pressure Port
Manifold Pressure Outlet
On/Off Switch
