Raypak Pool Heater Error Codes
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Featured codes
- Air Flow Sw Open / Air Flow Sw Closed / Fan Lockout — The inducer airflow switch did not match the fan state; three fan-switch faults in on
- Aux Ctrl Fault 2 / 3 / 5 / 6 / 8 — Digital-control ROM, RAM, analog-reference, multiplexer, or clock fault.
- Blocked Vent / Vent Temp Limit — The vent safety or vent-temperature limit is open.
- Clock/Fireman Sw — Fireman or remote switch in the safety loop is OFF
- Fan RPM Fault — Actual fan speed differs from target by more than 500 RPM.
- Flue Over Temp / Flue Sense Fail / Blocked Drain — The flue is too hot, its sensor failed, or the condensate-drain switch is closed.
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Safe checks with an external tool or supply
These pages list the check you can do from outside the unit, with an optional external tool or maintenance supply. None of them repair an internal fault.
- Air Flow Sw Open / Air Flow Sw Closed / Fan Lockout — The inducer airflow switch did not match the fan state; three fan-switch faults in one demand create lockout.…
- Blocked Vent / Vent Temp Limit — The vent safety or vent-temperature limit is open.…
Other pool-heater references
The same fault families appear across brands:
Related troubleshooting guides
Manufacturer manuals
A codes
- Raypak Air Flow Sw Open / Air Flow Sw Closed / Fan Lockout error code
The inducer airflow switch did not match the fan state; three fan-switch faults in one demand create lockout.… - Raypak Aux Ctrl Fault 2 / 3 / 5 / 6 / 8 error code
Digital-control ROM, RAM, analog-reference, multiplexer, or clock fault.…
B codes
- Raypak Blocked Vent / Vent Temp Limit error code
The vent safety or vent-temperature limit is open.…
C codes
- Raypak Clock/Fireman Sw error code
Fireman or remote switch in the safety loop is OFF…
F codes
- Raypak Fan RPM Fault error code
Actual fan speed differs from target by more than 500 RPM.… - Raypak Flue Over Temp / Flue Sense Fail / Blocked Drain error code
The flue is too hot, its sensor failed, or the condensate-drain switch is closed.…
H codes
- Raypak H2O Sensor Fail error code
Water-temperature sensors are open, shorted, or disagree.… - Raypak Harmonics or whining noise error code
Check U.G. (unitized gas valve) movement in hot water above 110 deg F. Look for debris or restriction in the water or gas line. Low flow can allow sca… - Raypak Heater cycles on and off continuously error code
Clean or replace a dirty filter, raise a low pool water level, adjust the external bypass, or adjust an out-of-spec pressure switch.… - Raypak Hi Water Temp / Hi Limit 1 Fault / Hi Limit 2 Fault error code
Water exceeded 108°F or a high-limit circuit opened.…
I codes
- Raypak Ign Ctrl Fault 2 / 3 / 5 / 6 / 7 error code
Ignition-control ROM, RAM, analog, flame-sense, or execution fault.… - Raypak Ignition Failure / Ign 60 min Delay / Ignition Lockout error code
Flame was not established within the permitted trial sequence.… - Raypak Ignition Lockout error code
Pilot flame not established, or lost during trial for main burner…
L codes
- Raypak Liming or scale forming in the exchanger error code
Correct pool water chemistry first. Inspect the bypass for movement and replace if none; replace the U.G. if it doesn't move when heated.… - Raypak Low Temp Lockout / Low Voltage error code
Water is below 36°F, or control supply is below 20 V.…
M codes
- Raypak MV Output Fault / Flame w/o CFH error code
The gas-valve output is wrong or flame is sensed with the valve closed.…
S codes
- Raypak Sooting error code
Reduce high flow rates with a manual bypass valve (target 105-110 deg F outlet). Check U.G. movement, air starvation, improper venting, and insects or…
T codes
- Raypak Takes too long to heat pool or spa error code
Confirm the heater isn't undersized for the pool gallonage, reset the time clock for adequate filter run time, clean a dirty filter, and confirm the g…
W codes
- Raypak WPS Stuck Closed / Water Sw Open error code
The water-flow switch does not match the current operating state.…