Raypak B-195 - Manual (Page 9)

9
A drain valve is provided in the tank for draining
water during servicing.
The temperature and pressure relief valve is easily
accessible through the front. A nipple is provided
(shipped loose with the heater) for installation in the
T & P relief valve. A drain line must be connected to
the nipple and run to a safe place of disposal.
WARNING: Failure to do so can cause water damage
or burns due to scalding if the relief valve should open.
Drain line must be as short as possible, pitch downward
from the relief valve, and have the same size as the
valve discharge connection through-out its entire length.
Refer to tag attached to T & P relief valve.
The temperature and pressure relief valve should
be manually operated at least once a year to insure that
the valve mechanism is still functional. Repair or
alteration of valve in any way is prohibited by National
Safety Standards and or local codes.
If the relief valve discharges occasionally or peri-
odically, this may be due to thermal expansion in a
closed water supply system. Contact the water sup-
plier or the local plumbing inspector on how to correct
this situation. DO NOT plug the relief valve or install
a shut-off valve in the discharge drain line.
The heater is equipped with a circulator to provide
the minimum water flow in the heater, and maintain a
uniform water temperature in the tank. Depending on
heater distance from the dishwasher, it may be neces-
sary to run empty rack(s) to purge supply of line lower
than the required 180°F water temperature. For this
reason, it is best to locate heater as close as possible
to the dishwasher.
CAUTION: In severe cold weather, freezing air can be
drawn through the vent pipes to the heat exchanger
during overnight shut-down period. If there is no water
circulation or heat in the water, freezing can occur
which will damage the heat exchanger. To avoid
freezing damage, constant water circulation should be
maintained by keeping the booster heater energized
so that the circulator (pump) will run. Closing the
manual gas shut-off valve will prevent unnecessary
heating of the water. NOTE: Under this condition, the
ignition system will go into a lock-out mode. To resume
service, the heater will need to be reset by momentarily
turning the ON/OFF switch to the OFF position, and
then to the ON position.