Repair manual

www.webasto.us 29 Webasto Thermo & Comfort N.A., Inc.
DBW 2010/2020/300 COOLANT HEATERS TROUBLESHOOTING
5.3.6 HEATER SMOKES
YES
NO
Is combustion air
intake or exhaust
outlet dirty?
Are the gas passages
(fins) of the heat
exchanger highly
soiled?
Motor r.p.m. too low
Clean if necessary,
correct installation
according to
instructions
Clean according to
instructions.
(see Sec. 9.1.1.3)
Does heater smoke
only during start-up?
Has the air intake
bellows been
incorrectly set?
Are there restrictions
or kinks in the fuel
return line?
Has the correct fuel
been used according
to the operating
instructions?
Observe the
recommendations
in the operating
instructions
Because of the return
fuel pressure, the flow
of the fuel nozzle is
too high
Let heater burn freely
(warm up to temp.)
Are the permissible
combustion values
adjustable?
(see section 10.3)
Does the heater
continue to smoke
after adjustment?
Motor r.p.m. too low
Gap distance between
the impeller and the
housing too great
(DBW 2010 and
Scholastic only)
Check fuel pump
pressure; is the pump
pressure too high?
Is battery voltage,
when charged,
below 10 V
resp. 20 V
Charge batteryAdjust according
to instructions.
(see Sec. 6.2.5)
Replace fuel nozzle