eta eHACK 20-50 kW, Service Manual

Page: 31 / 76

Cleaning and maintenance Maintenance (expert)
31
Clean heat exchanger
Scrape off the ash on the inner walls and remove the
fly ash from the heat exchanger, with an ash vacuum
for example.
Fig. 2-70: Heat exchanger
Check heat exchanger tubes
Check the heat exchanger tubes and the turbulators
for tar deposits.
Fig. 2-71: Heat exchanger tubes
Tar deposits can have several causes, for
example:
• leak air through the heat exchanger cover, the
combustion chamber door or the lambda probe.
• an incorrectly calibrated lambda probe
• overly moist wood chips
• insufficient boiler runtime (start-stop operation)
Check seal on heat exchanger cover
Inspect the integrity of the seal on the heat exchanger
cover and replace if necessary.
Fig. 2-72: Heat exchanger cover
CAUTION!
Avoid operation with damaged seals
Never operate the boiler with damaged seals.
Otherwise, leak air is sucked in, disturbing the
combustion process and causing increased wear.

Always replace seals as soon as they are
damaged.
Close heat exchanger cover
Place the heat exchanger cover and tighten the nuts
evenly and cross-wise.
Fig. 2-73: Heat exchanger cover