Hayward Pool Heater HF Error Code

Updated 2026-08-29 · review status: manual-verified Last verified: 2026-08-29

Quick answer

Flame Present / Gas Valve Off Flame detected when gas valve should be closed—serious safety condition requiring immediate attention. Shut down heater and close manual gas valve immediately. Do not attempt to restart. This requires professional service—a leaking gas valve is a serious safety hazard.

Severity: high · DIY difficulty: intermediate

Safety

TBD - must be written per-code before publish

What HF means

Flame Present / Gas Valve Off Flame detected when gas valve should be closed—serious safety condition requiring immediate attention. Shut down heater and close manual gas valve immediately. Do not attempt to restart. This requires professional service—a leaking gas valve is a serious safety hazard.

Causes, ranked

  1. 1. Flame sensed with gas valve off - lockout; blower runs until corrected common pro-only

    Check:

    Fix:

  2. 2. Sticky gas valve or flame-sensing fault occasional pro-only

    Check:

    Fix:

Parts & supplies for Hayward Pool Heater: filters, control boards, sensors, and common replacement parts.

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Commonly searched as: "hayward hf" · "hayward error code hf" · "hayward air conditioner hf"

Sources

  • PoolDial error-code reference (manual-backed) — verified 2026-08-29
  • Hayward H-Series H150FD-H500FD Service & Installation Manual (Figure 27: Error codes) — verified 2026-08-29
  • PoolDial error-code reference (manual-backed) — verified 2026-08-29