Main Burner Pressure - Vaillant ECOmax VUW 236 EH Instructions For Installation And Servicing

•
Push the right hand button once.
The display will now show the per-
centage range rating of the central
heating (compared to the maximum
nominal output for domestic hot
water). (Note: The factory set maxi-
mum figure is 80)
•
Remove screw (1, fig. 41) and
lower control panel.
•
Remove cover screw (2, fig. 42) to
access the range rating potentio-
meter beneath.
•
The central heating output can now
be altered by inserting an electri-
cians screwdriver into the potentio-
meter and turning. (See Table 4 for
the required output settings).
•
The selected rating will be display-
ed on the boiler display as adjust-
ments are made.
•
After setting, refit cover screw (2,
fig. 42) and resecure control panel
(1, fig. 41).
•
Push both buttons under the boiler
display simultaneously. The flow
temperature will now be displayed.

5.10 Main burner pressure

The burner pressure on this boiler has
been factory set and does not require
adjustment. The main burner pressure
may be checked in the following way:
•
Ensure the maximum hot water
temperature control (4, fig. 36) is
set to '9'.
•
Fully open a hot water tap to fire
the boiler at full rate.
•
Put the boiler into diagnostic mode
by pushing the two buttons (1 and
2, fig. 40) below the diagnostic dis-
play simultaneously until a `d' code
is displayed.
•
Push the left hand button to step
through the various `d' codes until
the screen shows the `d.20' code.
•
Push the right hand button once.
The display will now show the main
burner pressure in Pascals
(100 Pa = 1 mbar).
•
Check that the burner pressure is as
shown in Table 5. (If the burner
pressure is not correct within the
tolerance shown contact Vaillant
Ltd. Technical Department).
•
Turn off the hot tap.
fig. 41
Table 4: Central Heating Output (Range Rating)
Range rating
(Diagnostic Code
d. Ø reading)
80 (Maximum)
70
60
50
47 (Minimum)
Table 5: Burner Pressure & Gas Rate
Maximum Burner
Pressure (DHW)
(d. 20 reading)
Maximum Gas
Rate (DHW)
fig. 42
Output to Central Heating kW (Btu/h)
(with return temperature = 60 °C)
VUW 236 E
17.2 (58,700)
15.1 (51,500)
12.9 (44,000)
10.8 (36,800)
9.9 (33,800)
VUW 236 E
300 Pa ± 30 Pa
2.38 m /h
3
(84.04 ft 3 /h)
VUW 286 E
21.3 (72,700)
18.6 (63,500)
16.0 (54,600)
13.3 (45,400)
12.3 (42,00)
VUW 286 E
300 Pa ± 30 Pa
2.96 m /h
3
(104.52 ft 3 /h)
29