Raypak WH 0195A - Manual (Page 23)

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These instructions are primarily intended for the use of qualified personnel specifically trained and experienced in the
installation of this type of heating equipment and related system components. Installation and service personnel may
be required by some states to be licensed. Persons not qualified shall not attempt to install this equipment nor
attempt repairs according to these instructions.
PROBLEM(S)
1)When tankstat is turned on, heater
does not operate.
2)When tankstat is calling for heat,
pump is on, but burners will not turn
on.
CAUSE(S)
1)No power to the heater.
2)Defective tankstat or disconnected
wire in thermostat circuit.
3)Defective transformer.
1) For Standing pilot models pilot burner
not lighted.
2) If pilot burner will not stay lighted,
thermocouple or gas valve may be
defective.
3)Gas knob in "Pilot" position.
4)Vent switch is open.
5)Roll-out switch is open.
6)Manual Reset High limit is open.
7 ) Defective ignition module or
defective gas valve.
SOLUTION(S)
1)Check circuit breakers, disconnect
switch. Make sure power is on.
2)Check continuity on thermostat and
wiring circuit. Replace thermostat, or
repair wiring connections.
3) Check secondary voltage. If no 24V,
replace transformer.
1) Light pilot burner. (Follow lighting
instructions on rating plate).
2) Check thermocouple MV generation.
If less than 25MV (open circuit), re-
place thermocouple. If between 25-
35 MV, replace gas valve.
3) Turn knob to "ON" position.
4) Check for blockage of venting sys
tem or disconnected vent piping. After
problem is corrected push button to
reset vent switch.
5) Check for blockage of flue or sooted
heat exchanger. After problem is
corrected push button to reset
roll-out switch.
6) Check water flow and adjust to
obtain 8° to 10°F temperature rise.
7)On Honeywell module, check voltage
across terminals MV and MV/PV. If
no 24V is present, replace module. If
24V is present, replace gas valve.
TROUBLESHOOTING