Installation / Operation Instruction Manual
56
Maintenance and service
RTG-K-199/160N/X1 – 6 720 817 984 (2022/06)
Air Filter
• Verify if the air filter is clean and undamaged.
The air filter is attached to the fan assembly, see fig. 54.
• Air filter must be cleaned or replaced in case it is clogged or
damaged.
How to remove/assembly air filter,
▶ Disconnect the electrical supply from the water heater.
▶ Remove appliance front cover, see page 12.
▶Loosen two philips head screws.
▶ Remove air filter from the fan.
▶ Proceed in the reverse order for assembly.
Fig. 54 Remove/assembly air filter
NOTICE:
Appliance malfunction!
▶ Air filter should not be removed during appliance normal
operation as, it may increase the risk of burner blockage.
NOTICE:
Risk of burner blockage!
▶ Optional paper filter (part # 8738725270) can be
installed on the air fan for increased protection against
dusty, dirty combustion air or heavy pollen entering the
combustion chamber to reduce the risk of burner blockage.
In areas with high solid particles content in the air it is
recommended to use this filter. Maintenance frequency
might need to be adjusted to keep the filter clean and allow
a good performance of the heater.
7.2 Winterizing for seasonal use
The water heater must not be installed in a location where it
may be exposed to freezing temperatures unless connected to
electrical power. All water must be drained from the heater in
order to avoid damage to the unit from exposure to freezing
temperatures.
NOTICE:
The use of agents such as anti-freeze is not permitted and voids
the warranty, as they may cause damage to the water heater's
internal components.
1. Press ON/OFF switch on the water heater to turn OFF the
heater and unplug power supply cord. The display should
be blank.
2. Shut off the gas supply to the water heater.
3. Shut off the water supply to the water heater using installer
supplied shutoff valve.
4. Open hot water taps to drain and relieve pressure from the
plumbing system. If water continues to flow after 5
minutes, a crossover of the hot and cold water pipes is
present and must be corrected before proceeding.
5. Disconnect inlet and outlet water pipes from the water
heater. Place a small bucket underneath the water heater to
catch residual water remaining inside the water heater.
6. Using an air compressor, blow short bursts of air (100psi
max) through the inlet water connection or inlet water filter
until there is no water present coming through the outlet
water connection of the heater.
7. Empty condensate trap.
8. Reconnect the water fittings, refill the condensate trap and
return the heater to service when danger of freezing has
passed.
7.3 Mineral scale build-up
Periodic descaling may be necessary in areas with high mineral
content in the water, (see table 17, Water Quality). Scale
buildup in the heat exchanger may result in lower flow rates,
error codes of AA, E3 and E5 and boiling sounds in the heat
exchanger.
A water softener is required if the water hardness exceeds 12
grains/gal (200 mg/l) calcium carbonate. Damage to the water
heater resulting from hard water/scale deposits will not be
covered under warranty.
Descaling using a pump
▶ Disconnect electrical supply from the water heater.
▶ Shut off the water supply to the water heater using (installer
supplied) shutoff valve.
▶ Open hot water taps to drain and relieve pressure from the
plumbing system.
▶ Drain water from the unit's heat exchanger by
disconnecting inlet and outlet water connections from the
heater.
▶ Remove the caps from both inlet and outlet drain
connections.