Why Are 4,600 Hayward Pool Heaters Being Recalled for Carbon Monoxide Risk?

What the heater looks like and where it was sold

The recalled unit is a 400,000 BTU dual-fuel gas heater branded Hayward HDFS400 Universal-HC Series. It stands 31 inches high. The cabinet is 28 inches wide and 21 inches long. The cabinet is brown with a black top. A digital display control panel sits at the top. The base is molded with integrated tie-down connections. The name plate sits below the vent. The word "Hayward" appears at the bottom of that plate. The model number "HDFS400" appears at the top.

Pool equipment distributors sold these heaters nationwide. Builders and service professionals also sold them. Sales ran from March 2026 through July 2026. The price was about $5,600. Hayward Industries, Inc. of Charlotte, North Carolina manufactured them in the United States. The recall carries number 26-777 and was announced September 17, 2026.

How the carbon monoxide gets into the air

During operation the heaters can produce high levels of carbon monoxide. The notice does not explain which component fails or why combustion goes wrong. It states the hazard plainly: high CO output while the heater runs. Carbon monoxide has no smell. It has no color and no taste. A person breathing it feels headache and dizziness. Nausea follows before losing consciousness. Death follows if exposure continues. The heater sits outdoors but venting can push exhaust toward occupied spaces. Wind shifts matter. Proximity to windows or doors increases the risk. Covered patios nearby add the same risk.

No injuries have been reported. The notice says "None reported." That does not mean no one breathed the gas. It means no incident has reached the commission's record.

What the repair covers and how to get it

Consumers should stop using the pool heater immediately. The remedy is a free in-home inspection and repair by a qualified technician. Hayward Industries arranges the visit. Owners call toll-free 855-500-528