Raypak 407A Swimming Pool Heater User Manual


 
38
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
1. With pump and heater
on, turn adjustment
knob clockwise until a
click is heard from the
gas valve.
2. Turn adjustment knob
counter-clockwise 1/4
turn.
3. Turn pump off and on
several times. Heater
should shut off immedi-
ately. If it does not,
repeat the above steps.
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.
TWO-SPEED PUMPS
In some cases, the flow on the low-speed is insufficient
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.
PRESSURE SWITCH
ADJUSTMENT RANGE
CAUTION:
Do not operate the heater without the
function of a properly adjusted water pressure switch
or flow switch.
FLAME ROLL-OUT SAFETY SWITCH
Atmospheric heaters are equipped with a thermal cut-
off device to prevent flame roll-out in the event the
heat exchanger becomes blocked. This is a "single-
use" type fusible link or thermal fuse, that must be
replaced when disabled by an over-temperature condi-
tion, 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
1. Shut off main elec-
trical 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.# 9440
Fig.# 9439
Fig.# 9438
5 FT.
MAX
POOL OR SPA
MAY REQUIRE ADJUSTMENT
FOR LOWER PRESSURE
MAY REQUIRE ADJUSTMENT
FOR HIGHER PRESSURE
5 FT.
MAX
Fig.# 8152.3