Raypak Pool Heater Aux Ctrl Fault 2 / 3 / 5 / 6 / 8 Error Code

Updated 2026-08-30 · review status: manual-verified · reviewed by MiniSplitDecoder Editorial Team Last verified: 2026-08-30

Check your model first

  • Professional Series X94
  • Professional Series SR-410
  • X94 / SR-410 (Professional Series Digital)

Match the model on your equipment label to the linked manufacturer documentation. The same code can mean different things across model families.

Quick answer

Digital-control ROM, RAM, analog-reference, multiplexer, or clock fault.

Severity: high · DIY difficulty: easy

Safety

Stop at the exterior: power-cycle at the disconnect, clean the filter/basket, and check for obvious water-flow blockage. Pool heaters combine gas piping, 240 V wiring, and (on heat pumps) refrigerant — burner, control-board, and sealed-system work requires a licensed technician. If you smell gas, shut the gas valve and leave the area first.

What Aux Ctrl Fault 2 / 3 / 5 / 6 / 8 means

Digital-control ROM, RAM, analog-reference, multiplexer, or clock fault.

Code meaning varies by series

  • X94 / SR-410 (Professional Series Digital): Aux Ctrl Fault 2: ROM CRC failure on digital control board. 3: RAM failure. 5: A/D Reference failure. 6: A/D Multiplexor failure. 8: Unable to read time of day clock.

First checks before service

This page currently documents the safe reset triage. If the code returns, use the linked source manual or a qualified technician for code-specific diagnosis.

  1. 1. One-time fault event (power disturbance or transient sensor reading) common DIY

    Check: Power-cycle at the breaker/disconnect (or unplug for CPAP), restore, and run the system while watching for the code.

    Fix: If the code does not return after a full run cycle, the fault was transient — monitor, no repair needed.

  2. 2. Fault persists after a clean reset occasional pro only

    Check: If the code returns immediately or every session, note the conditions (startup, heating, after rain).

    Fix: A persisting code points at the component the manual assigns to this code — that repair is technician territory.

Commonly searched as: "raypak aux ctrl fault 2 / 3 / 5 / 6 / 8" · "raypak error code aux ctrl fault 2 / 3 / 5 / 6 / 8" · "raypak pool heater aux ctrl fault 2 / 3 / 5 / 6 / 8"

Sources

Related Pool Heater guides

Hayward Pool Heater Error Codes: Safe Checks