7
EN1R-9134 0503R20NE
ADJUSTMENTS
WARNING
Adjustments must be made by qualified persons only.
If the appliance manufacturer supplies checkout and/
or service and maintenance instructions carefully
follow them.
If such instructions are not provided then use the
procedure outlined below.
Adjustment can only be made with a special tool.
Pressure tap
The gas control is provided with a pressure tap of 9 mm O.D.
at inlet and outlet side.
When checking the pressure undo the screw a half turn and
slip tube over nipple.
Ensure that screw is retightened after making test.
CAUTION
To ensure a safe closing of the valves, it is essential
that voltage over the terminals of electric operators is
reduced to 0 Volt.
Offset adjustment (see fig. 1.)
•
Remove cap screw with a Torx T-40 screw driver or 5 mm
hex key to expose offset adjustment screw.
•
Check gas supply pressure to the appliance using a
pressure gauge connected to the inlet pressure tap.
•
Start fan and check air flow.
•
Energize both electric operators in order to have gas input
to burner and ignite boiler.
•
Adjust CO
2
% at the desired value at low output with
offset adjustment screw. Turn offset adjustment screw
clockwise to increase CO
2
%.
•
Operate boiler on high output. (Only modulating
applications).
•
Replace cap screw and tighten pressure taps.
CHECKOUT
•
After any adjustment check pressure taps and gas
connections with an approved leak detection fluid for gas
leakage.
•
After any adjustment set appliance in operation and
observe a complete cycle to ensure that all burner
components function correctly.
MAINTENANCE AND SERVICE
Under normal circumstances no maintenance or service is
required.
WARNING
Do not disassemble the gas control; it contains no
replaceable components.
Attempted disassembly or repair may damage the
gas control
Screws on the valve that have been sealed must
never be removed.
