Learn what common AVIA display messages mean, which homeowner-safe checks can help, when a reset may be appropriate and which conditions require qualified heater service.
A Raypak AVIA fault message identifies the system preventing normal heating. You can safely record the message, confirm the pump is running, clean the filter if needed, verify valves are open and check that gas service has not been shut off. Do not bypass switches, adjust gas pressure or repeatedly reset a returning fault. Messages involving flame without a call for heat, gas-valve faults, soot, gas odor or recurring lockouts require qualified service.
The AVIA uses full-text status and fault messages instead of relying only on short abbreviations. That makes the display easier to understand, but the message is still a starting point rather than a complete diagnosis.
A low-flow message may come from a dirty filter, incorrect valve position, scale, a weak pump or a pressure-switch issue. An ignition failure may involve the gas supply, ignition system, combustion air, venting or an internal component. The safest approach is to use the message to identify the affected system and then limit homeowner troubleshooting to basic external checks.
What to Do When the AVIA Displays a Fault
AVIA Water Flow and Temperature Faults
| Display Message | Plain-English Meaning | Homeowner-Safe Checks | Recommended Response |
|---|---|---|---|
| Water Sw Open | The water pressure switch is not proving adequate circulation. | Confirm the pump is running, water level is correct, valves are open and the filter is not dirty. | Check circulation |
| Low Flow Fault | The heater detects low flow through the heat-exchanger system. Scale may also contribute. | Check pump speed, filter pressure, valve position and visible flow restrictions. | Service if persistent |
| High Flow Fault | The heater detects excessive flow conditions. Raypak notes possible condensation. | Confirm pump speed and whether the system bypass was recently adjusted. | Hydraulic adjustment |
| Flow Sensor Fail | The optional flow sensor is reporting an out-of-range value. | Confirm normal circulation. Do not alter sensor wiring. | Qualified service |
| Hi Limit 1 Fault | The first high-temperature safety limit opened. | Check water flow, filter condition and pump operation. | Correct flow first |
| Hi Limit 2 Fault | The second high-temperature safety limit opened. | Check circulation and stop if the condition repeats. | Service if repeated |
| Outlet Over Temp | The heater measured outlet water above 180°F. | Confirm the pump is operating and valves are correctly positioned. | Stop and inspect flow |
| Low Temp Lockout | Water temperature is below the heater’s low-temperature operating threshold. | Confirm actual water temperature and freeze conditions. | Protect from freezing |
| Sensor Misplaced | The inlet and outlet sensors may be installed incorrectly or the readings do not match expected flow direction. | Confirm normal pump operation and whether plumbing work was recently completed. | Qualified inspection |
AVIA Ignition, Flame and Gas Faults
| Display Message | Plain-English Meaning | Homeowner-Safe Checks | Recommended Response |
|---|---|---|---|
| Ign Try Failure | The heater did not ignite during the first or second attempt. | Confirm the external gas supply is on and other gas appliances are operating normally. | Service if repeated |
| Ign 60 min Delay | The gas valve failed to establish operation three times during one call for heat. The heater enters a 60-minute delay. | Do not repeatedly cycle power. Confirm gas service has not been interrupted. | Allow lockout, then service |
| Ignition Lockout | A configured single-try ignition attempt failed and the heater locked out. | Check only the external gas supply and record the message. | Qualified diagnosis |
| Flame Lost | Flame was established but was no longer detected while heating. | Check whether gas service is stable. Do not access the burner compartment. | Combustion service |
| Flame w/o CFH | The control senses flame when the gas valve should be closed. | No homeowner repair should be attempted. | Stop and call service |
| Gas Valve Fault | The control senses the gas valve on when it was commanded off. | Do not reset repeatedly or access gas controls. | Stop and call service |
Air, Fan and Venting Faults
Air SW Open
The air-pressure switch did not prove expected airflow. Check for an obvious blocked air inlet, but leave internal testing to a technician.
Vent Sw Open
The vent-air switch opened. Outdoor blockage, an improper vent system or another airflow condition may be involved.
Fan Lockout
Three air-switch faults occurred in the same heating demand. The underlying airflow problem should be diagnosed.
Diff Sw Fault
The differential-pressure switch failed to prove expected operation. Fan or power-supply issues may be involved.
Flue Over Temp
Flue temperature exceeded the published limit. Stop operation and have combustion, flow and heat transfer inspected.
Flue Extreme Low
Flue temperature is below 140°F. Raypak identifies this as a service-required condition because condensation may occur.
AVIA Sensor and Communication Faults
| Display Message | What It Indicates | Recommended Response |
|---|---|---|
| In Sensor Fault | The inlet thermistors disagree by more than 3°F. | Have the sensor assembly, wiring and water-flow conditions inspected. |
| In Sensor Open | The inlet sensor circuit is open or reporting an extremely low value. | Qualified sensor and wiring diagnosis is required. |
| In Sensor Short | The inlet sensor circuit is shorted or reporting an extremely high value. | Qualified sensor and wiring diagnosis is required. |
| Out Sensor Open / Short | The outlet water sensor has an open or shorted circuit. | Do not operate until the sensor circuit is inspected. |
| Flue Sensor Open / Shrt | The flue-temperature sensor is outside its valid electrical range. | Qualified service is required. |
| No Communication With Ignition | The user interface cannot communicate with the ignition board. | Internal harness and board communication must be inspected. |
| Internal Fault / EEPROM Fault | The controller has detected a memory or internal-board fault. | A reset may be attempted according to the manual, but a returning fault may require board service. |
| Low Voltage | The control is receiving less than the expected 24VAC supply. | Electrical input and transformer output require testing. |
What Does “Call Service” Mean on a Raypak AVIA?
The AVIA displays Call Service after recurrent faults indicate that the heater, gas system, venting or water system may require attention. It is not a diagnosis of one specific failed part.
Raypak identifies the message as an automatic-recovery fault after a 60-minute lockout. Certain earlier firmware versions also include a display-guided procedure for clearing the message. Clearing the message does not repair the cause.
Should You Reset an AVIA Fault?
A single temporary fault caused by a dirty filter, closed valve or interrupted utility may clear after the external condition is corrected. However, a reset should not be the first response to every message.
Use this troubleshooting order
- Photograph the exact fault message.
- Check pump operation, pool water level, filter condition and valve position.
- Check for visible leaks, blocked airflow or an interrupted external gas supply.
- Correct only the safe external condition you can clearly identify.
- Allow the heater to recover or follow the manual’s approved reset process.
- If the fault returns, stop resetting and arrange service.
The AVIA program menu includes an option to clear stored fault history. Fault history is valuable diagnostic information, so do not erase it before a technician has had an opportunity to review the issue.
Information to Give the Service Technician
Model and Serial Number
Photograph the heater rating label and confirm natural gas or propane.
Exact Fault Message
Provide a photo rather than describing the message from memory.
When It Occurs
Explain whether the fault appears immediately, during ignition or after several minutes of heating.
Pump and Filter Status
Include pump speed, filter pressure and whether circulation appears normal.
Recent Changes
Mention plumbing work, router changes, gas service, winter opening or automation adjustments.
Equipment-Pad Photos
Wide photos help show valves, plumbing, venting, pump and chemical equipment.
Raypak AVIA Error Code FAQ
What does Low Flow Fault mean on a Raypak AVIA?
What does High Flow Fault mean?
Why does the AVIA say Ign Try Failure?
What does Flue Extreme Low mean?
Can I clear the Call Service message?
Why does the fault return after I reset the heater?
Can Raymote show AVIA faults?
Need Help Identifying an AVIA Part or Replacement Option?
Send Aqua Terra Backyard the exact fault message, heater model and serial number, gas type and clear equipment-pad photos. We can help identify the correct documentation, compatible part or replacement direction.
Shop Gas Pool Heaters Contact Aqua Terra BackyardThis guide explains display messages but does not replace qualified gas-heater diagnosis. Never bypass safety devices or perform gas, combustion or internal electrical service unless properly trained and authorized.