Addison UHAS 150, Installation, Operation & Service Manual

Page: 41 / 74

SECTION 11: O
PERATION AND
M
AINTENANCE
33 of 59
11.2.2 Start-Up the Gas Valve (All Gases)
11.2.2.1 Check Burner Gas Pressure
1. Remove the plug in the outlet (burner) pressure
test point and connect a pressure tap and a
manometer.
2. With the burner firing, measure the pressure on
the manometer. To adjust the burner pressure,
remove the regulator cover from the valve and
turn the regulator adjustment screw to set the
required burner pressure as stated in the
Technical Data Table for the correct gas and
model on Page 57, Section 16.3 and Page 59,
Section 16.6 .
NOTE: For two stage valve (High/Low operation)
check burner pressure in both operating modes. To
adjust the burner pressure, remove plastic cover
from regulators and adjust High and/or Low
regulators as needed.
NOTE: If the correct burner pressure cannot be
reached, then check the inlet pressure to the valve
with the burner firing. See Technical Data Table
on
Page 57, Section 16.3 and Page 59, Section 16.6 for
inlet pressure requirement.
Do not continue to adjust the regulator if the
pressure is not changing.
If the inlet pressure is too low to allow correct burner
pressure setting, then the gas inlet pressure must be
corrected before completing the start-up.
11.2.2.2 Check Gas Rate
1. After burner pressure adjustment, allow the
heater to operate for at least 15 minutes and
then re-check settings. Adjust pressure setting
if necessary.
2. Check gas flow rate at gas meter. For two stage
valve (High/Low operation) check gas flow in
both operating modes.
3. Turn off heater and electrical supply.
4. Remove the manometer and refit all covers to
the valve and tighten the screw of the outlet
pressure tap.
11.3 Pressure Switch
The pressure switch is factory pre-set for each
model and is not adjustable.
11.4 Turning Off the Heater
Set the thermostat to the "OFF" position or lowest
setting and the main burner will stop.
The fan will continue to run until it is stopped
automatically by the fan thermostat.
Do not use a disconnect switch for control of
heater. Disconnect switch will turn off the fan.
Heat exchanger could be damaged. Warranty will
not cover damage to the heat exchanger if
operated improperly. Only use the disconnect
switch for turning off heater for service or during
off-season.
11.5 External Controls
External controls may include time switch, interlock
switch, room thermostat and frost thermostat.
Operate each control to ensure that they function
correctly. Set the switches (if fitted) and
thermostat(s) to the users’ requirements.
11.6 Complete the Start-Up
Ensure that all covers are fitted correctly and all test
points are properly sealed.
11.7 Instruction to the User
Explain the controls of the heater to the user
including how to turn it on and off, using the controls
fitted on site.
Give this manual to the user.
Ensure that the user is shown and understands the
importance of maintaining clearances to
combustibles
on Page 7, Figure 3 , installer
responsibility on Page 4, Section 2 and user
instructions on Page 34, Section 12 and all
warnings defined in this manual.