Whirlpool · Hybrid HPSE2K50/66/80
Whirlpool Hybrid HPSE2K50/66/80 error code SF
What it means
The air filter is dirty.
What Whirlpool says to do
1. Turn off power at the circuit breaker/fuse box. 2. Clean the air filter. See "Air Filter Cleaning/Replacement" section.
Last checked 2026-10-03.
Safety first
- Before attempting to clean or replace the air filter or condensate drain pan/lines, turn off power to the water heater at the circuit breaker/fuse box. (pg. 15)
- WARNING Electric Shock Hazard: Disconnect power before servicing. Replace all parts and panels before operating. Failure to do so can result in death or electrical shock. (pg. 16)
From the manufacturer's manual for this series.
The same code on other models
Codes mean different things on different heaters. Match the series to the model number on your rating label.
- A. O. Smith Voltex hybrid with letter codes (HPTU, 2016–2019): SF
- A. O. Smith Early Voltex hybrid (FPTU, 2015 manual): SF