Adjusting The Central Heating Output (Range Rating) - Vaillant turboMAX pro 24/2 E Instructions For Installation And Servicing

7 Gas supply adjustments (Commissioning Part II)
Set the DHW temperature control to maximum and fire
the boiler at full rate by fully opening a hot water tap.
Check that the burner pressure is as the maximum
shown in table 7.1.
Measure the domestic hot water mode burner operating
pressure (mbar), the heat input (kW), the inlet and outlet
domestic hot water temperatures (°C) and flow rate
(l/min) and record details in the boiler logbook.
After completion of all tests tighten sealing screw,
replace the sealing plug and check all test points for
soundness (1/1a).
7.3 Adjusting the central heating output (range
rating)
The boilers are fully modulating for central heating, and
it is therefore not necessary to range rate the boiler.
However, if desired, it is possible to range rate the boiler,
as follows:
• Connect the U-gauge to check burner pressure.
• Use Table 7.1 on to determine the central heating
output required.
• Identify required range rating setting and note main
burner pressure in mbar for that output.
• Turn on the central heating.
• Turn the central heating maximum radiator tempera-
ture control to its highest setting.
• Ensure that any thermostatic radiator valves are open
and set to high.
• Wait for approx. 2 minutes until the burner pressure
switches to full load.
• The central heating output can now be altered by ins-
erting an electricans screwdriver into the
potentiometer (2).
• Turn the potentiometer fully anticlockwise.
• Slowly turn the potentiometer clockwise, whilst
observing the U-gauge.
• Stop turning the potentiometer when the burner pres-
sure is at the correct setting for the output required.
• Turn off the hot tap.
• Remove U-gauge, tighten test point sealing screw (1).
• Reassemble the boiler.
• Refit plastic plug in chamber sensing tube.
• Carry out all safety checks as detailed in these
instructions.
• Record central heating operating pressure in the
Benchmark gas boiler commissioning checklist along
with the heat input (kW) and temperature difference
between flow and return.
Attention!
DO NOT open any hot water tap while carrying
out this procedure (turboMAX plus only).
22
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2
Fig. 7.3: Adjusting the central heating output
Note!
This illustration shows the U-tube pressure
gauge connected to a system configured to run
on natural gas. When connecting the U-tube
pressure gauge to a system running on LPG,
please refer to Fig. 7.2 on page 21.
Instructions for Installation and Servicing turboMAX pro R3
1
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