Brands & error codes
Raypak pool heater error codes
Raypak's digital gas heaters (models 206A, 266A, 336A and 406A) spell out what's wrong in words on the display. These meanings come from Raypak's own installation and operation manual. Older or other Raypak models can show different messages, so check your manual.
If you smell gas, stop
Normal status messages
Not every message is a problem. With no active faults, Raypak lists three normal messages:
| Display | What it means |
|---|---|
| Heating | The heater is being asked for heat and the flame is lit. |
| Spark | The igniter is sparking to light the heater. |
| No Demand | The water has reached the set temperature, so the heater isn't being asked for heat. |
Messages when it's calling for heat
Raypak says these show only while there's a demand for heat.
| Display | What it means |
|---|---|
| Water Sw Open | The water pressure switch is open. The heater isn't seeing enough water flow from the pump, so it won't fire. |
| Vent/Field Sw #1 | The vent spill switch (or a field-added switch) is open. |
| Hi Limit 1 is open / Hi Limit 2 is open | A high-temperature limit switch opened. On ASME units only, it's a manual reset: press MODE. |
| Rollout Sw Open | The flame rollout switch opened. This is a combustion safety switch: leave it off and call a qualified tech. |
| Flow/Field SW #2 | A field-supplied flow switch (or other field switch) is open. |
| Ignition Lockout / Ignition Failure | The pilot didn't light in time ("No pilot sensed"), or the pilot was lost while lighting the main burner ("Main Ign Failure"). |
| Ign 60 min Delay | The pilot was lost 4 times while lighting the main burner. The heater locks out for 60 minutes, then tries again. |
Fault messages
| Display | What it means |
|---|---|
| Sensor Failure | The temperature sensors disagree by more than 2°F. |
| Sensor Open / Sensor Short | A temperature sensor has failed open or shorted. |
| Flame w/o CFH | The board senses a flame when the gas valves should be shut. Turn the heater off and call a qualified tech. |
| PV Output Fault | The pilot gas valve output isn't doing what the board told it to. |
| LoNox Tab Fault | The board sees a Lo NOx signal on a heater that isn't a Lo NOx model. |
| Internal Fault / EEPROM Fault | A control board or memory fault. |
| Clock/Fireman Sw | The time clock or fireman's switch circuit is open. |
| Low Temp | Water temperature is below 36°F. |
Two safe first checks
- Flow first. For Water Sw Open, and for a high limit that trips, make sure the pool pump is running and the filter and baskets are clean, and run a variable-speed pump faster while you test. Raypak says its water pressure switch lets the heater run only when the filter pump is on, and that its pressure switch should be set by a qualified service person, so don't adjust or bypass it.
- Pump run time. Raypak's fix for high limit events is to confirm the circulation pump runs during the whole heating cycle, and that the pump shuts off at least 5 minutes after the heating cycle ends. Otherwise leftover heat can trip a high limit. If your timer or automation shuts the pump off with the heater, that's worth a look.
If the message comes back with good flow, or you see Rollout Sw Open, Vent/Field Sw #1, an ignition, sensor or board message, stop there. Those involve gas, venting, combustion or control parts, and Raypak says they're for a qualified service tech.
Get a tech on video
On a video call a tech can read the exact message, look at the rating plate, the plumbing and the pump settings, and tell you whether it's flow, a timer setting, or a part such as a pressure switch, sensor or igniter. You'll know what you need before anyone orders a part. For other brands, see pool heater won't fire.
Common questions
What does Water Sw Open mean on a Raypak heater?
The water pressure switch is open, so the heater isn't seeing enough water flow from the pump and won't fire. Check that the pump is running and the filter and baskets are clean. Raypak says the pressure switch should be adjusted only by a qualified service person.
Why does my Raypak heater say Hi Limit is open?
A high-temperature limit switch opened. Raypak says to confirm the pump runs during the whole heating cycle and keeps running at least 5 minutes after heating ends, so leftover heat doesn't trip the limit. On ASME units it's a manual reset with the MODE button. If it keeps happening, contact a qualified tech.
What does Ign 60 min Delay mean on a Raypak?
The pilot flame was lost 4 times while the heater was trying to light the main burner, so it locks out for 60 minutes before retrying. Make sure the gas supply is on. If it repeats, call a qualified tech: ignition and gas parts aren't owner repairs.
What does Rollout Sw Open mean?
The flame rollout switch opened. It's a combustion safety switch. Leave the heater off and have a qualified tech check it.
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Read the guideSources
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