Checking The Burner And Cleaning The Heat Exchanger - Baxi Assure 500 Combi Series Installation And Service Manual

10 Maintenance
Fig.71 Removing the air-gas system
66 Assure 500 Combi 2
10.3.7

Checking the burner and cleaning the heat exchanger

Warning
Dust released from the front insulation panel and the rear
insulation panel can harm your health.
Clean the heat exchanger with only a soft brush and water.
Avoid contact with the rear and front plate
Do not use steel brushes or compressed air.
Danger
In the case of maintenance/disassembly of the boiler combustion
circuit installed on a collective flue in positive pressure, take the
necessary precautions to prevent the fumes from other boilers
installed on the collective flue from entering the room where the
boiler is installed.
Proceed as described below for cleaning:
1. Isolate the unit from the power supply (disconnect the boiler from the
main power supply).
2. Cut off the gas supply to the boiler.
3. Close the hydraulic cocks.
4. Remove the front panel.
5. Remove the entire air-gas unit, unscrew the screw (A) and the clip (B)
located between the fan and the gas valve.
6. Remove the silencer (C).
7. Unscrew the 4 M6 locknuts (D) on the burner door.
8. Check the condition of the detection/ignition electrode. Replace the
electrode if necessary.
9. Check the condition of the burner, the gasket and the insulation panel.
10. The burner does not require any maintenance, it is self-cleaning.
Check that there are no cracks and/or other damage on the surface of
11.
the dismantled burner. If the burner is damaged, replace it. Replacing
12. the burner flange gasket.
13. Check the front insulation panel for cracks, damage, moisture, ageing
and deformation. Replace the insulation panel if in doubt.
14. To clean the upper part of the heat exchanger (combustion chamber),
use a vacuum cleaner and a brush with plastic bristles.
Thoroughly clean with the vacuum cleaner again without the end
15.
piece (brush).
Make sure (using a mirror, for example) that there is no visible dust
16.
residue. Vacuum up any residue.
It is forbidden to clean the combustion chamber with any unauthorised
17.
chemical products and, in particular, ammonia, hydrochloric acid,
sodium hydroxide (caustic soda) etc.
Generously wet the surfaces to be cleaned using a manual sprayer
18.
containing a solution of water and vinegar. Do not use it on
excessively hot surfaces (max. 40 °C). Wait approx. 7-8 minutes then
brush the surface without rinsing it. Repeat the process. Wait another
8 minutes and then brush again. If the result is not satisfactory, repeat
the operation.
19. Rinse with water. The water will flow out of the heat exchanger
through the condensate drain siphon. Wait another 20 minutes and
use a powerful water jet to wash away the dirt particles. Do not aim
the water jet directly at the insulating surface on the rear of the heat
exchanger.
20. To re-assemble, perform the above actions in reverse order.
Caution
The maximum tightening torque of the four M6 nuts (D) fastening
the flange is 5 Nm ( +/- 0.5).