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The Raytherm Low NOx Heater is offered with WH1-
On-Off firing (standard) or 2-stage firing (optional).
The heaters are certified and tested under the latest
edition of the ANSI Z21.10.3 standard for hot water
heaters.
The heater should be installed to meet all local codes,
the National Fuel Gas Code ANSI Z223.1, and the
National Electrical Code, ANSI/NFPA 70-latest edition.
OPERATION
On call for heat, the ignition system, consisting of an
electronic spark module, gas pilot system is energized.
Providing pilot is proven, blower will start running, the
main gas valve will open and the heater will operate.
When the operating control is satisfied, the heater will
shut down.
START-UP PROCEDURES
(S8610B Ignition Module)
1.Turn on power to the heater with gas supply off.
2.Check ignition module as follows:
a. Set the thermostat or controller to call for heat.
b. Watch for continuous spark at the pilot burner.
c. Check the ignition spark operation. Time must be
within the lockout timing period (15 or 90 seconds).
d. Turn control down to end call for heat and wait 60
seconds on lockout models before beginning step
3.
ADDENDA: LOW NOx HEATERS Models 181 to 401
35
Fig # 9361
HIGH GAS PRESSURE SWITCH
Pressure switch senses high pressure and automati-
cally shuts down burner if abnormal pressure exists.
Fig. #8236.0
PRESSURE
SWITCH
GAS MANIFOLD
BURNER ADJUSTMENT
This burner assembly does not require any primary air
adjustments.
VISUAL INSPECTION
Flame can be observed through the slot opening above
the plenum. Flame color is blue and evenly spread on
the top surface of the burner. A visual inspection
should be made monthly of the burners. In case flame
lifting is observed on the burner, check gas pressure on
manifold and static pressure in plenum. Gas pressure
in manifold should be 3.9" WC and static pressure in
plenum should be greater than 0.5" WC
ELECTRICAL
Be sure that electrical service to the heater has proper
overload fuse or circuit breaker protection, and wire
size and connections comply with all applicable codes.
3.Turn on gas supply.
4.Set controller to call for heat.
5.System should start as follows:
a. Spark will turn on and pilot gas valve will open and
the blower will begin running.
b. Heater will operate until call for heat is satisfied.