11
9.
Water Piping
This appliance is suitable for potable water. Do not use this appliance if any part has been underwater. Immediately
call a qualifi ed service technician to inspect the appliance and replace any part of the control system and gas control
which has been under water.
If the water heater is installed in a closed water supply system, such as one having a backfl ow preventer in the cold
water supply line, means shall be provided to control thermal expansion. Contact ANDREWS WATER HEATERS
TECHNICAL DEPARTMENT FOR ADVICE.
Piping and components connected to the water heater shall be suitable for use with potable water.
Toxic chemicals, such as those used for boiler treatment, shall not be introduced into the potable water.
A water heater used to supply potable water may not be connected to any heating system or components previously
used with a nonpotable water heating appliance.
When water is required in one part of the system at a higher temperature than in the rest of the system, means
such as a mixing valve shall be installed to temper the water to reduce the scalding hazard.
• Flush water through the pipe to clean out metal powder, sand and dirt before connecting it.
• Take appropriate heat insulation measures (e.g., wrapping with heat insulation materials, using electric heaters)
according to the climate of the region to prevent the pipe from freezing.
• Use a union coupling or fl exible pipe for connecting the pipes to reduce the force applied to the piping.
• Do not use piping with a diameter smaller than the coupling.
• When feed water pressure is too high, insert a depressurizing valve, or take water hammer prevention measures.
• Avoid using joints as much as possible to keep the piping simple.
• Avoid piping in which an air holdup can occur.
• Use approved piping materials.
• If installing the unit on a roof:
If the unit is installed on a roof to supply water to the levels below,
make sure that the water pressure supplied to the unit does not
drop below 2000 mbar. It may be necessary to install a pump system
to ensure that the water pressure is maintained at this level.
Check the pressure before putting the unit into operation.
Failing to supply the proper pressure to the unit may result in
noisy operation, shorter lifetime of the unit, and may cause the
unit to shut down frequently.
Supply water piping
• Do not use PVC piping.
• Mount a check valve and a shut off valve (near
the inlet).
• In order for the client to use the water heater
comfortably, 1000 mbar to 5000 mbar of pressure
is needed from the water supply.
Be sure to check the water pressure. If the
water pressure is low, the water heater cannot
perform to its full capability, and may become a
source of trouble for the client.
Drain piping
• Expansion water may drop from the pressure
prevention device and wet the fl oor. If necessary,
provide drain piping or use a drain hose to
remove the water.
Hot water piping
• Do not use lead or PVC piping.
• The longer the piping, the greater the heat loss.
Try to make the piping as short as possible.
• Use a mixing valve with a low water resistance.
Use shower heads with low pressure loss.
• If necessary, use a pump or other means to
ensure that the supply water pressure to the
inlet of the heater does not fall below
2000
mbar
when the maximum amount of water is
being demanded. Also install a pressure meter
on the inlet. If this is not done, local boiling will
occur inside the water heater causing abnormal
sounds and decreasing the durability of the heat
exchanger.
Ask a qualifi ed plumber to perform the installation
of the plumbing. Observe all applicable codes.
WATER QUARITY
If the heater is in a hard water area a suitable water conditioning device must be installed to prevent the build up of limescale
within the heat exchanger. Heat exchangers damaged by scaling are not covered by the manufacturer’s warranty.
Description
pH
Total
Dissolved solids
(TDS)
Total
Hardness
Chlorides
Magnesium
Calcium
Sodium
Iron
Maximum
Recommended Levels
6.5 - 9.0
500
mg/liter
150
mg/liter
250
mg/liter
10
mg/liter
20
mg/liter
180
mg/liter
1
mg/liter
Completely insulate
the water inlet and
outlet fittings.
Insulate the water
supply valve completely.
Do not cover the water
drain plug with insulation
so that water in the pipe
can be drained.
