50
GAS PRESSURE ADJUSTMENTS WITH HONEYWELL VK 4105 VALVE
All boilers are tested and calibrated in the factory. At first ignition it is necessary to check and set up the boiler
to adapt it to the system characteristics. The gas pressure at the burner must be checked through the pressure
plug placed on the pipe coming out from the gas valve and by using a water column pressure gauge or a
micro-manometer. The values must be those indicated in the specific table. When all calibrations have been
completed, close and seal the pressure plug used. Calibration of the slow ignition is electronically done and is
adjustable (for optimising and for gas type conversion) by the trimmer
RLA
on the electronic board. The
necessary thermal output for the heating system can be regulated by acting on the trimmer
R.MAX
. By remov-
ing the
JP4
bridge, the waiting time for boiler restarting can be varied, after its stop when reaching the
temperature selected on the heating potentiometer. (bridge off: 2,5 minutes)
MODULATION MAXIMUM PRESSURE ADJUSTMENT
●
remove the protecting cover
G
●
place the “function selector” on TEST position
●
tighten (to increase) or untighten (to decrease) the adjustment bolt
H
MINIMUM PRESSURE ADJUSTMENT
After the maximum pressure adjustment has been completed proceed with the following operations:
●
disconnect the power wire (12 V) from the modulation coil
●
tighten (to increase) or untighten (to decrease) the adjustment bolt
I
●
connect again the modulation coil power wire (12 V) (“function selector” must always be on TEST position)
●
replace the protecting cover
G
Once adjustments have been effected, replace “function selector” on Summer or Winter.
J P 4
J P 1
J P 3
J P 2
J P 5
R L A
R m a x .
Adjustment trimmer
RLA
Adjustment trimmer
R. MAX
Note: “Function selector” places on “TEST” only for combustion test. This function stops gas pressure on
maximum output for 15 minutes.
For this calibration it is necessary to use a water column pressure gauge connected to the pressure
plug.
H
G
I
Burner pressure
intake
