Technical data

35
8.0 maintenance
and inspection
8.1 maintenance procedure
After 365 operating days (8760 hours) the message ‘service’ appears in the display. The following work
must then be carried out:
1. Refer to the user with regard to any known problems, or any other comments about the appliance.
2. We recommend that the fault data from the boiler control panel be read via a lap top computer and
RS-232 interface. The service software is available from MHS Boilers Ltd. The cause of frequent faults
must be identified and corrected.
3. Check the flow and return water connections for soundness.
4. Check the system pressure. Minimum 0.5bar.
5. Remove the casing panels and check the general condition of the boiler visually. Any evidence of
leakage must be corrected.
6. Remove the burner. Check the primary heat exchanger for contamination. If required, the primary
heat exchanger can be cleaned with a vacuum cleaner or a nylon brush, do not use a PVC or a steel
brush. It is not normal to clean or gain access to the flueways of the secondary heat exchangers, for
further information, please contact the Technical Department.
Note: The burner must never be touched with the hand and must never be cleaned mechanically, this can
cause damage to the surface.
7. Check the bolts for fixing the burner lance to the burner plate. The bolts must be tightened if required.
8. Check the gap between the ignition electrode and the burner (4 to 5mm). If required, bend the ignition
electrode cautiously. Do not touch the surface of the burner.
9. Empty and flush out the condensate siphon located behind the rear panel of the boiler.
10. Check the combustion fan for contamination. If required this must be cleaned.
11. Measure the CO and the CO
2
content in the exhaust gas. If necessary regulate the combustion (see
section 6).
12. Check the gas carrying components for soundness.
After this maintenance has been carried out, press and hold the ‘service’ button for 10 seconds. The
service signal is then deleted from the display. If the maintenance is carried out before expiration of the
service interval and if no service signal has yet appeared in the display, the service button must be pressed
for 10 seconds. The indication (SERVICE) appears in the display and the already counted days are set to
zero (‘0’). For this procedure the boiler must not be in fault condition with a flashing display.