Kärcher HDS3.5/20 Operator's Manual page 27

2. TO CLEAN BURNER JETS:
Select proper size drill for type gas involved. Use
pin vise to hold drill and ream out each jet orifi ce.
CAUTION: Do not ream out orifices to a
larger size.
If the water heater will be exposed to freezing weather,
an anti-freeze solution should be circulated through the
coil by whatever means are available for the particular
system the water heater is used on.
To Adjust Pressure Regulator
Adjustment of the pressure regulator is not normally
necessary since it is preset at the factory. However,
fi eld adjustment may be accomplished as follows:
1. Manometer attachment may be accomplished at
the pressure tap plug.
2. Remove regulator adjustment screw cap (see
Figure 5, page 23).
3. With small screwdriver, rotate adjustment screw
clockwise to increase, or counterclockwise to
decrease pressure.
4. Replace regulator adjustment screw cap.
MAINTENANCE & SERVICE
9.801-509.0 - C • Karcher Operator's Manual
27