Installation / Operation Instruction Manual

57
Troubleshooting
RTG-L-199/160N/X1 – 6 721 827 274 (2022/06)
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.
▶ Connect a line (A) from the outlet of the circulating pump
(installer supplied) to the inlet water fitting on the water
heater (see fig. 55).
▶ Using another line (B), connect the water outlet fitting on
the water heater. Route the other end of this line into a
descaling reservoir.
▶ Using a 3rd line (C) from the descaling reservoir, connect to
the inlet side of circulating pump. Install a filter on the end
of the line in the descaling reservoir.
▶ Make sure all connections are "water tight.".
▶ Fill tank with descaling solution so both lines inside are
submersed. We recommend a straight white vinegar
solution. If using a commercial descalant, refer to
manufacturer's instructions for proper dilution ratio.
▶ Operate the circulating pump.
▶ Make sure there are no leaks and the solution is flowing
from the descaling reservoir through the heater and
returning to the reservoir.
▶ Run solution through the heater until the solution returning
to the descaling reservoir comes out clear. (Changing to a
fresh solution may be necessary during this process).
▶ Disconnect all lines and drain all solution from heat
exchanger. Properly discard of solution.
▶ Attach the cap to the inlet drain connection to close it.
▶ Position a container below the hot water outlet and connect
cold water supply. Open cold water supply shutoff valve
and flush heat exchanger with clean water.
▶ Shut cold water shutoff valve and reconnect hot water
supply to the water heater.
▶ Attach the cap to the outlet drain connection to close it.
▶ Reconnect electrical supply to unit, open water shutoff
valves, and return the unit to service.
Fig. 55
[1] Pump
8Troubleshooting
DANGER:
If you are unable to perform the tasks listed below, or need
additional assistance,
▶ Please contact a service provider or contractor.
NOTICE:
In some areas local code may require that the tasks described
in this section must be performed by a certified contractor.
▶ Check your local codes to ensure compliance.
8.1 Introduction
Many of the questions customers ask regarding operation of
this unit can be answered by following the troubleshooting
steps as outlined below. For best results, perform each step