The H-Series has been the workhorse above-ground gas heater for years, and this version brings it up to date. The new Universal Display sits under a weather-sealed lid on the top of the cabinet and gives you the same control layout whether you're running the heater on its own, on a Hayward Omni system, or on most competitive automation panels. With OmniX built in, you can pair the heater to your phone for scheduling, temperature changes, status messages, and real-time fault diagnostics — no separate controller or add-on board required.

Underneath, it's the H-Series you already know. The cupro-nickel heat exchanger is standard, not an upgrade, so it holds up in salt-chlorinated pools and forgives the water chemistry swings that eat through copper. Hayward's "totally managed" water flow moves heat into the pool quickly and lets you shorten pump run time, and low-NOx combustion keeps it compliant with clean-air standards. Service happens entirely from the front panel — no pulling the heater away from a wall or fence line to get at the back.

Wiring is about as simple as it gets: the heater ships with a 3' power cord and a standard 120V plug, so there's no hard-wiring and no electrician needed on the power side. Rated for above-ground pools and spas and intended for outdoor installation only. Gas heaters must be installed by a licensed professional in accordance with local code.

FEATURES

• 135,000 BTU natural gas — sized for above-ground pools and spas
• OmniX embedded intelligence: remote control, scheduling, and diagnostics from your phone
• Universal Display — consistent controls across Omni, OmniX, and most competitive automation systems
• Standard cupro-nickel heat exchanger; salt- and chemistry-tolerant
• "Totally managed" water flow for fast speed-to-heat and reduced pump run time
• Low NOx emissions — meets clean air quality standards
• Includes 3' power cord with standard 120V plug — no hard-wiring required
• Front-panel-only access for service and maintenance
• Outdoor installation only; professional installation required
• Hayward SKU: W3HS135FDN (propane version: W3HS135FDP)
• Replaces the discontinued W3H135FDN