Brands & error codes
Hayward pool error codes
These meanings come from Hayward's troubleshooting guide for the Universal H-Series heater, the MaxFlo VS pump manual and the AquaRite manual. Other models can differ, so check yours.
Universal H-Series heater
| Code | What it means |
|---|---|
| LO | Water pressure switch, vent pressure switch or temperature limit switch fault. Check flow first. |
| IF | Ignition failure. Retries 3 times, locks out, waits 60 minutes, retries 3 more, and keeps retrying every 60 minutes while there's a call for heat. |
| HS | Return water above 105°F, or a rise of more than 6°F within 60 seconds (a sign of low flow). |
| AO / AC | Blower vacuum switch open (AO) or closed (AC). |
| IO | Ignitor circuit open. |
| HF | Flame present with the gas valve not energized. Shut it down and call a tech. |
| SF | Temperature sensor (thermistor) input failure. |
| PF | Voltage polarity reversed or low voltage. |
| CE | Communication error between the control module and display. |
| BD / EE / SB | Board faults (BD, EE) or keypad failure (SB). |
MaxFlo VS pump: Check System messages
| Message | What it means |
|---|---|
| DC voltage too high / too low | Supply voltage problem. Hayward says line voltage should be within 10% of the pump's rating. |
| Drive is overheated | Internal drive too hot. Clear anything blocking the motor's airflow. |
| Drive overload / Pump failed to start | Motor current too high or it couldn't start: check for binding in the impeller, diffuser, seal or motor. |
| Motor phase lost / Processor failed / Memory failed / Drive comm failed | Internal drive or motor problems; Hayward says the motor/drive may need replacing. |
| Communication failed | The user interface and drive aren't talking; check the connection between them. |
Hayward says errors can be reset with Stop/Resume or by cycling power, and some overload errors only by cycling power.
AquaRite salt system
No Flow, Check Salt, High Salt and Inspect Cell are covered in salt cell codes.
What you can safely do
- For LO and HS: check the pump is running, the filter and baskets are clean and the valves are open.
- For IF: make sure the gas supply valve is open, and let it go through its retries.
- For HF, IO, SF, PF and board codes, and any pump drive fault that repeats: call a qualified tech.
Common questions
What does LO mean on a Hayward pool heater?
On the Universal H-Series, LO means a fault on the water pressure switch, vent pressure switch or temperature limit switch. It's not a low temperature reading. Check water flow first: pump, filter, baskets and valves.
What does IF mean on a Hayward heater?
Ignition failure. The heater retries 3 times, locks out, then retries every 60 minutes while there's a call for heat. Make sure the gas supply is on; if it keeps failing, call a qualified tech.
How do I reset a Hayward variable-speed pump error?
Hayward's MaxFlo VS manual says errors can be reset by pressing Stop/Resume while the message shows, or by cycling power. If it comes back, the cause still needs fixing.
Related guides
Heater won't fire
No heat, a flow or pressure code, or an ignition lockout. Flow comes first.
Read the guideVariable-speed pump codes
Priming, overheat, overcurrent and voltage alarms across the big three brands.
Read the guideSalt cell / chlorinator codes
No Flow, Check Salt, Inspect Cell and what the IntelliChlor LEDs mean.
Read the guidePentair error codes
MasterTemp ERR PS, HLS, IGN, AGS; IntelliFlo3 alarms; IntelliChlor lights.
Read the guideSources
- Hayward, Universal H-Series heater troubleshooting guide (UHS16b): diagnostic codes and failure-to-light sequence
- Hayward, MaxFlo VS variable speed pump (SP2303VSP) owner's manual: Check System messages
- Hayward, AquaRite salt chlorination owner's manual (092540 Rev G): water chemistry, indicator LEDs, cell inspection and troubleshooting
Brand names belong to their owners. Pool Helpline isn't affiliated with or endorsed by any manufacturer. Steps and codes vary by model and year, so always check your own owner's manual.
