John Wood Concentric Vent - JW98-DVC - Manuel (Page 17)

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Supply water piping
• Do not use PVC, iron, or any piping which has been
treated with chromates, boiler seal or other chemicals.
• Mount a check valve and a shut off valve (near the inlet).
• In order for the client to use the water heater
comfortably, 98.1 to 491 kPa (14 to 70 PSI) 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 floor. If neces-
sary, provide drain piping or use a drain hose
to remove the water.
Hot water piping
• Do not use lead, PVC, iron or any piping which
has been treated with chromates, boiler seal or
other chemicals.
• The longer the piping, the greater the heat loss.
Try to make the piping as short as possible.
• Use mixing valves with low water resistance.
Use shower heads with low pressure loss.
• If necessary, use a pump or other means to en-
sure that the supply water pressure to the inlet
of the heater does not fall below 29 PSI when
the maximum amount of water is being demand-
ed. 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.