Sta-Rite Max-E-Therm Heaters & Parts

Sta-Rite Max-E-Therm Pool & Spa Heaters

The Sta-Rite Max-E-Therm is Pentair's high-performance gas pool and spa heater, available in 200,000 and 400,000 BTU sizes for natural gas and propane, plus HD and ASME versions. Pool Supply Depot carries Max-E-Therm heaters and genuine replacement parts. Order online with nationwide shipping or pick up at our Henderson, NV store.

Size	Natural gas	Propane
200K BTU	200K NG (SR200NA)	200K LP (SR200LP)
400K BTU	400K NG (SR400NA) · 400K NG HD (SR400HD)	400K LP (SR400LP) · 400K LP ASME (460764)

Which Max-E-Therm size do I need?

The quick formula is gallons × 8.34 × temperature rise (°F) ÷ hours to heat = BTU per hour. Spas and smaller pools are often well served by 200K BTU, while larger pools and pool/spa combos benefit from 400K BTU for faster heat-up. See our pool heater BTU sizing guide.

Standard, HD or ASME?

Standard Max-E-Therm (SR200NA/LP, SR400NA/LP) – the right fit for most residential pools and spas.
HD models (SR400HD) – a cupro-nickel heat exchanger for more demanding water conditions and heavy use.
ASME models – certified for commercial pools and installations where code requires it.

Always order the fuel type that matches your gas supply, and confirm gas-line capacity, venting and clearances for your install. Conversion kits are available when switching between natural gas and propane.

Max-E-Therm replacement parts

The Max-E-Therm shares many components with the Pentair MasterTemp, and many problems are fixed with a single part. We stock the control board & membrane pad kit (461105Z), ignition control module (476223), igniter kit (77707-0054), gas valve (42001-0051S), combustion blower (77707-0253), high limit switch (42001-0063S), thermistor (42001-0053S), manifold kits, tube sheet coil assemblies and the pro service repair kit (461100). Parts are model-specific, so confirm the model and serial number on your heater before ordering, or send us a photo. Shop the full Pentair MasterTemp heaters & parts collection for more compatible components.

Sta-Rite heaters in Las Vegas & Henderson

Pick up your Max-E-Therm heater or parts at Pool Supply Depot, 121 Industrial Park Rd, Suite 109, Henderson, NV, with same-day pickup on in-stock items, or order online with nationwide shipping. Call 725-205-1783. Shop all pool heaters & heat pumps.

Max-E-Therm FAQ

What is the difference between the SR400NA and the SR400HD?
Both are 400K BTU natural gas Max-E-Therm heaters. The SR400HD uses a cupro-nickel heat exchanger built for tougher water conditions and heavier use.

Do MasterTemp parts fit my Max-E-Therm?
Many do — the two heaters share a large number of components, and part titles in this collection note compatibility. Match your model and serial number first.