Winterizing For Seasonal Use; Mineral Scale Build-Up - Bosch C 1210 ES Installation Manual

Inlet Water Filter
• Verify the inlet filter screen is clean and undamaged.
The inlet water filter is located between the ¾" cold
water inlet fitting on the right side of the appliance,
and the water valve (See Fig. 33, page 29). Close
installer supplied water shutoff, carefully lift the water
valve, then rotate back. Remove filter, clean and or
replace if damaged.
Descaling
• In areas where the water supply has a high mineral
content, the heat exchanger should be flushed with a
descaling solution. Scale build up will shorten the life
of the water heater and damage resulting from scale
is not covered under warranty. Refer to section 6.3
for detailed instructions on descaling the heat
exchanger.
Fin Coils
• Inspect heat exchanger fin coil for soot build-up or
blockage. To access fin coil, consult service bulletin
at www.boschpro.com. If there is evidence of soot
build-up or blockage, the heat exchanger should be
removed by a professsional and cleaned thoroughly.
Condensate trap
• Check water level in the condensate trap,
see Fig. 35.
• If appliance is out of service for more than 10 days,
fill as described on page 31.
• Check for debris and clean if needed.
6.2

Winterizing for seasonal use

The water heater must not be installed in a location
where it may be exposed to freezing temperatures. If the
heater must be left in a space which is likely to
experience freezing temperatures, all water must be
drained from the heater. Freeze damage is not covered
under the warranty. NOTE: 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 gas supply to heater.
3. Shut off the cold 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
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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 outlet water connection
until there is no water present coming through the
inlet water connection of the heater.
7. Reconnect water fittings and return heater to service
when danger of freezing has passed.
6.3

Mineral scale build-up

Periodic descaling may be necessary in areas with high
mineral content in the water or if the heater is operating
in applications where the outlet temperature exceeds
140°F. Scale buildup in the heat exchanger may result
in lower flow rates, error codes of A7 and E9 and boiling
sounds in the heat exchanger.
A water softener is required if the water hardness
exceeds 6 grains/gal (103 mg/l) calcium carbonate.
Damage to the water heater resulting from hard water or
scale deposits will not be covered under warranty. See
Section 3.10 Water Quality.
Descaling using a pump
1. Disconnect electrical supply from the water heater.
2. Shut off the water supply to the water heater using
(installer supplied) shutoff valve.
3. Open hot water taps to drain and relieve pressure
from the plumbing system.
4. Drain water from the unit's heat exchanger by
disconnecting inlet and outlet water connections
from the heater.
5. Connect a line (A) from the outlet of the circulating
pump (installer supplied) to the inlet water fitting on
the water heater (see Fig. 65.)
6. Using another line (B), connect to the water outlet
fitting on the water heater. Route the other end of
this line into a descaling reservoir.
7. 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.
8. Make sure all connections are "water tight.".
9. 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.
10. Operate the circulating pump.
11. Make sure there are no leaks and the solution is
flowing from the descaling reservoir through the
heater and returning to the reservoir.
12. 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).
Maintenance and service
41