HAMWORTHY HEATING LTD
19
Wessex ModuMax
mk3
Boilers
500001308/C
Note:
-
Main Gas Supply Pressures are as follows;
Natural Gas
-
20mbar, LPG
-
37mbar.
TO CHECK B
1)
Turn off the electrical power and gas to the appliance.
2)
Connect the manometer assembly to test point (Fitted on the inlet to the gas valve).
3)
With A and B closed open C and monitor manometer over a 2 minute period, a rise indicates a leak on valve B.
TO CHECK A
1)
Open C.
2)
Open B to produce the mains gas supply pressure between A and B.
3)
Close B.
4)
System may be considered sound if over a period of 2 minutes any drop in pressure is less than 0.5 mbar
Note:
-
Allow a manometer stabilisation period of approximately 1 minute before each 2 minute check period. Following
soundness tests close valve B and remove manometer connections and tighten test points.
7.2 Refer to Appendix A, Gas Data Tables, for maximum inlet pressure for normal operation.
The Following checks must be made prior to lighting the boiler;
Figure 7.2.1
-
Gas Isolating Valve (97 & 116 shown)
1. Ensure that the gas supply is connected, but the
boiler module gas service (isolating) valve(s) are
closed
, any unions or fittings are correctly tightened
and test points are
closed
.
2. Ensure the electrical mains supply is correctly
connected but the boiler module isolator(s) are
switched off
. Check all wiring loom connections such
as fan or gas valve are correct and secure. Remove
the clip, limit stat bulb and tension spring from the
pocket in the front of the heat exchanger, and
carefully apply a heat source to the bulb.
Note
-
take care not to damage the tension spring in
removal and replacement!
Check the continuity with a meter. If satisfactory, refit
the bulb and tension spring in the pocket and secure
with the clip. Ensure that all thermostat bulbs are fully
inserted into their pockets. The flow and return sensor
bulbs are located at the rear of the boiler in the flow
and return pipes.
3. Check setting of both temperature limiter and control thermostat. The temperature limiter is factory set at 95
°
C.
The control thermostat is set using the rotary dial on the fascia as detailed in
the separate User Instructions,
HHL part
no. 500001309.
4. The flame ionisation signal generated whilst the boiler is firing, can be viewed directly from the display by
accessing information level. The value is set to read dc
μ
A. Refer to
the separate Navistem manual,
HHL part
no. 500001310.
5. To ensure correct ignition of the boiler it is recommended to check the resistance of the hot surface igniter. This
should be checked cold, using a suitable ohmmeter, by disconnecting the igniter from the control panel cable and
measuring the resistance across the pins of the 2 way connector. The reading should be between 70 & 200 ohms
refer to figure 7.2.3
6. Before ignition of the boiler it must be ensured that all parts of the appliance are clean and free from debris.
Special attention should be paid to ensuring that the inlet to the venturi via the air filter is clean and unobstructed.
7. Ensure the heating system circulation / shunt pump is operational and that the pipework is free of air.
8. The flame ionisation signal generated whilst the boiler is firing, can be viewed directly from the display screen.
The value is set to read dc
μ
A.
