Form 44201129
Oct 2019 rev A
12
A.
Combustion Air Adjustment (System Cold)
It is necessary to adjust the amount of combustion air to each burner in the system by carring out the
following procedures:
1.
Switch off the electricity supply to each appliance in the system.
2.
Turn off the gas supply to each appliance in the system, at their gas isolation valves.
3.
Set the adjustable gate of each appliance damper (after unscrewing the clamp screw) such that the stop
(rivet) is positioned against the damper housing ie. position of maximum resistance to air flow. Secure the
adjustable gate in position with the clamp screw. See Fig. 12 below.
Fig 12
4.
Activate the exhaust fan by switching on the electricity supply to the system control and setting the time
switch and thermostat to demand heat. Carry out the procedures at 5 and 6 on each of the appliances in the
system.
5.
Connect a suitable manometer (0.01 mbar resolution) to the test nipple protruding from the rear panel of the
control box (adjacent to the air inlet adaptor) as outlined in separate installation and operation instructions
manual supplied with the heater.
6.
Reposition the adjustable gate of the appliance damper (after unscrewing the clamp screw) to attain a
negative pressure reading on the manometer of 1.5mbar ± 0.05mbar. Secure the adjustable gate in position
with the clamp screw
7.
Finally, check all the test points again to verify that the negative pressure at each of the burners in the system
is 1.5mbar ± 0.05mbar.
Carry out the procedures of B below on each appliance in the system.
