Viessmann Vitogas 050 ECD Series Installation & Service Manual page 16

Boiler servicing – heat exchanger cleaning
A service/inspection of the boiler and the system is mandatory
once a year.
Before heating season starts, boiler/burner should be serviced
by a qualified service agency. The owner should establish a
service contract with a qualified service agency.
Cleaning heat exchanger (flue gas passageways,
see Fig. 11)
1. Disconnect power supply to boiler and all heating related
components.
2. Close main gas shut-off valve. Allow boiler to cool if
necessary.
3. Remove front panel.
4. Remove gas burner assembly from boiler (refer to gas
burner removal procedure, page 12).
5. Refer to Fig. 13 for draft hood removal. Disconnect vent
pipe from draft hood outlet.
6. Remove top panel from boiler (4 screws).
7. Remove rear panel (6 screws).
8. Remove screws securing mid panel, upper front panel and
control panel to side panels (4 screws per side).
9. Remove side panels (3 screws per side).
10. Remove top insulation and loosen insulation jacket to
reveal screws securing draft hood to cast iron heat
exchanger (4 screws). Remove screws.
11. Carefully pry draft hood from heat exchanger.
12. Clean fins by brushing diagonally through sections. See
Fig. 11.
13. Inspect combustion chamber by using flashlight between
front section legs.
14. Before reinserting burner manifold, clean stainless steel
burners with soft brush.
15. Inspect ignition system. Check igniter for cracks or other
deterioration. Replace if necessary.
16. Reverse steps 4 through 11 to reassemble boiler. Seal draft
hood to casting using a high temperature RTV type sealant.
16
Fig. 11
Cleaning heat exchanger
Additional check points of annual service inspection
Check flue pipe condition, chimney connection, and chimney
itself, both inside and outside, for rust, deterioration, blockage,
or leakage. Repair or replace as necessary.
Check pressure relief valve and system pressure, and verify
proper operation of automatic feed if installed.
Check heating pipe joints, valves, air vents, etc. System leaks
must be corrected immediately to avoid damages. The cause of
any system defect must be determined and corrected in order
to prevent property damage, personal injury, or loss of life.
Check for proper combustion air supply and ventilation for the
boiler.
Check to ensure that combustible material or chemicals are not
stored close to the boiler. Operate high limits by dialing lower
settings, switching burner on/off to verify function of same. If low
water cut-off is installed, check and verify proper function
according to manufacturer's instructions. If oil lubricated
circulating pump is used, check for proper lubrication.
Check for gas-tight connection of gas piping, unions, gas valve
and manifold.
Check proper ignition and gas burner operation.
Combustion test must be performed by a competent service
technician.
Do not tamper with boiler or controls.
Diagonal brush
application