Viessmann B1KE Combi Series Installation And Service Instructions Manual page 86

Troubleshooting
Fault Messages Fault Messages
Repairs
(continued)
1. Shut off and drain the boiler on the heating water
and DHW sides.
2. Undo screws.
3. Remove plate heat exchanger.
Note: During and after removal, small amounts of
water may trickle from the plate heat exchanger.
4. Remove gaskets and dispose of them.
5. Check connections on the DHW side for scaling.
Clean or replace the plate heat exchanger as required.
6. Check connections on the heating water side for
contamination. Clean or replace the plate heat
exchanger as required.
7. Install plate heat exchanger in reverse order using
new gaskets.
Screw torque: 28 lb.in ± 2 (3.2 Nm ± 0.2)
Note: During installation, ensure the connections are
positioned and the gaskets seated correctly.
WARNING
Risk of electric shock from escaping heating water or
DHW.
Check all water side connections for tightness.
86
(continued) (continued)
Vitodens 100-W, B1HE/B1KE Combi Installation/Service
Removing the hydraulic unit
If components of the hydraulic unit have to be
replaced.
Close the gas shut-off valve and secure against

unintentional reopening.
Isolate the system from the power supply, e.g. by

removing the separate fuse or by means of a mains
isolator, and check that it is no longer live.
Safeguard the system against reconnection.

Wear suitable personal protective equipment when

carrying out any work.
WARNING
Hot surfaces and media can cause burns or scalding.
Before maintenance and service work, switch

off the boiler and let it cool down.
Never touch hot surfaces on the boiler, burner,

flue system or pipework.
IMPORTANT
Electronic assemblies can be damaged by electrostatic
discharge.
Before beginning work, touch grounded objects, such
as heating or water pipes, to discharge any static.
Disconnect all water and gas connections.