Raypak 336A - Manual (Page 38)

FLAME ROLL-OUT SAFETY SWITCH
Atmospheric heaters are
equipped with a thermal cutoff
device to prevent flame roll-out
in the event the heat exchang-
er becomes blocked. This is a
"single-use" type fusible link or
thermal fuse, that must be
replaced when disabled by an
over-temperature condition, caused by excessive
restriction in the heat exchanger flue passage.
HIGH LIMITS
The heater is equipped with two automatic high limits.
Both are located in the inlet/outlet header. Both are set
to open at 135°F.
NOTE: An erratic high limit is often characteristic of an
internal heat exchanger problem, e.g. scale build-up,
defective bypass. Refer to Troubleshooting section (on
pg. 42).
HIGH LIMIT REMOVAL
38
1. Make sure the pool filter is
clean before adjusting the
switch.
2. Set the heater control to the
OFF mode.
3. Turn the filter pump on and
confirm that the pressure
TWO-SPEED PUMPS
In some cases, the flow on the low-speed is insufficient
PRESSURE SWITCH
ADJUSTMENT RANGE
CAUTION: Do not operate the heater without the
function of a properly adjusted water pressure switch
or flow switch.
1. Shut off main electrical
power switch to heater.
2. Remove inlet/outlet
inspection panel.
3. Remove defective high
limit and
replace with a new high
limit.
4. Replace inspection panel.
PILOT SAFETY - Millivolt Models
Heaters equipped with the standing pilot (millivolt sys-
tem) have pilot generators which act as a safety
device to shut off the flow of gas to the main burners
and the pilot burner in case the pilot flame is extin-
guished. The pilot burner must be manually re-lighted
to place the heater in operation again. Refer to the
lighting instructions provided on the heater label.
PILOT SAFETY - Digital Models
The heater employs a pilot safety which closes the
main gas valve within 8/10ths of a second whenever
the pilot flame is interrupted. The pilot flame is auto-
matically lit when the device is powered. The heater
performs its own safety check and opens the main
valve only after the pilot is proven to be lit.
Fig.# 9439
5 FT.
MAX POOL OR SPA
MAY REQUIRE ADJUSTMENT
FOR LOWER PRESSURE
MAY REQUIRE ADJUSTMENT
FOR HIGHER PRESSURE
5 FT.
MAX
Fig.# 8152.3
switch is closed (use a multimeter to check). If the
pressure switch fails to close, either the switch set-
ting is too high or not enough pressure is being
supplied by the filter pump.
4. Turn the heater ON.
5. Manually turn the pressure adjustment knob clock-
wise until the heater shuts off. (A flat screwdriver
may be necessary if knob is too tight.)
6. Slowly turn the adjustment knob counter-clockwise
until the heater calls for heat again.
7. Turn an additional 1/2 turn counter-clockwise.
8. While the heater is running, check the adjustment
by turning the pump off and on several times. The
burners should shut off immediately when the
pump is turned off. If it does not, repeat the above
steps until proper operation is observed.
Fig.# 9440
to operate the heater. This is apparent when the water
pressure switch cannot be further adjusted or if the
heater makes banging noises or shuts off on high limit.
In these cases, the pump must be run at high speed
when heating the water.
NOTE: If heater is installed outside of the limits
shown, a higher pressure rated (11 psi) switch may be
used. A flow switch, mounted and wired adjacent to the
heater, may be used in place of the factory-mounted
pressure switch. See Parts List (pg. 51) for 11 psi
water pressure switch.
WATER PRESSURE SWITCH
The water pressure switch, or heater actuator, ensures
that the heater operates only when the filter pump is in
operation. It is located on the inlet/outlet header. It is
factory set at 1.75 PSI for deck-level installations.
When the heater is located below the level of the spa
or pool, it may be necessary to adjust the pressure
switch to compensate for the no-flow static head. If it
is necessary to adjust the water pressure switch, uti-
lize the following procedure:
WATER PRESSURE SWITCH ADJUSTMENT
Fig.# 9438
Adjustment
Knob