Freeze protection system, Maintenance and service, Unit draining and filter cleaning – John Wood Takagi - 320H-520H User Manual

Page 29

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29

Household Flow Rates

Appliance/Use

Flow Rate

l/min

GPM (US)

Lavatory Faucet

3.78

1.0

Bath Tub

15.2 - 37.8

4.0 – 10.0

Shower

7.5

2.0

Kitchen Sink

5.6

1.5

Dishwasher

5.6

1.5

Washing machine

15.2

4.0

Taken from UPC 2006

Freeze Protection System

This unit comes equipped with heating blocks to protect
it against damages associated with freezing.
For this freeze protection system to operate there has
to be electrical power to the unit. Damage to the heat
exchanger caused by freezing temperatures due to
power loss is not covered under the warranty. In cases
where power losses can occur, consider the use of a
backup power supply.
The freeze protection system will activate when the sur-
rounding and/or outside temperatures drop below 2.5°C
(36.5°F).
In any areas subject to freezing temperatures, the manu-
facturer highly recommends an indoor installation with
the 520H model. In such an installation, freezing issues
can only occur if cold air enters through the venting into
the heat exchanger, whether by negative pressures
within the installation location or by strong outside winds.
It is the installer’s responsibility to be aware of these
issues and take all preventative measures. The manufac-
turer will not be responsible for any damage to the heat
exchanger as a result of freezing.
The manufacturer also highly recommends the use of a
back flow vent damper to minimize the amount of cold
air entering through the exhaust venting when the water
heater is off.
If you will not be using your heater for a long period of
time:

1. Completely drain the unit of water. Refer to pg. 29.

2 Disconnect power to your heater.
This will keep your unit from freezing and being dam-
aged.

CAUTION

Only pipes within the water heater are pro-
tected by the freeze protection system. Any
water pipes (hot or cold) located outside the
unit will not be protected. Properly protect
and insulate these pipes from freezing.

MAINTENANCE AND SERVICE

WARNING

Turn off the electrical power supply and
close the manual gas control valve and the
manual water control valve before servic-
ing.

Clean the cold-water inlet filter. (Refer to diagram
below)
Be sure that all openings for combustion and ventilation
air are not blocked.
Check that the exhaust vent pipe is not blocked.
Check the gas pressure.
Keep the area around the water heater clear. Remove
any combustible materials, gasoline or any flammable
vapors and liquids.

The manufacturer recommends having the unit checked
once a year or as necessary by a licensed technician.
If repairs are needed, any repairs should be done by a
licensed technician.

Unit Draining And Filter Cleaning

1. Close the manual gas shut off valve.

2. Turn off power to the unit,

and then turn on again.

3. Wait 30 seconds, and

then turn off power to the
unit, yet again.

4. Close the water shut off

valve.

5. Open all hot water taps

in the house. When the
residual water flow has
ceased, close all hot
water taps.

6. Have a bucket or pan to catch the water from the unit’s

drain plugs. Unscrew the two drain plugs (Large and
small) to drain all the water out of the unit.

7. Wait a few minutes to ensure all water has completely

drained from unit.

8. Clean the filter: Check the water filter located within the

cold inlet. With a tiny brush, clean the water filter of any
debris which may have accumulated and reinsert the
filter back into the cold water inlet.

9. Securely screw the drain plugs back into place. Hand-

tighten only.



Water
Valve

Drain Plug
with Filter

Gas
Valve

Drain Plug (Small)

Drain Plug

(Large)

Water
Valve

Drain Plug
with Filter

Gas
Valve

Drain Plug (Small)

Drain Plug

(Large)

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