By Sta-Rite



Model # SR400NA

Alternate Part #'s PENSR400NA

Product Description

Sta-Rite Max-E-Therm Pool and Spa Heaters are certified for outdoor or indoor installation. Features include an LCD temperature readout with dual thermostat controls, temperature safety lockout, and 6 position control panel. PMG burner technology requires no outdoor draft hood. Proven Dura-Glas Resin provides rust-proof construction.


  • Rust-Proof Enclosure - Unlike conventional metal enclosures, the Max-E-Therm is made of Dura-Glas® - a sleek, lightweight and rustproof material that withstands heat and the elements.
  • Exact Temperature Controls - Weatherproof temperature controls that can be set to your specifications.   Pivoting UV-resistant plastic visor covers the Digital Display.   Accommodates temperatures for both a pool and a spa running off of the same heater, in Fahrenheit (°F) or Celsius (°C).
  • Energy Efficient - PMG combustion technology improves Efficiency and reduces operating costs.  Also provides faster heat ups.  The three sizes available are 83% efficient or higher.
  • Safety - Internal safety feature sets maximum temperature levels.  Full diagnostic lights for troubleshooting problems.  The diagnostic indicator lights tell you whether to service the heater or the pump/filter system.
  • Environment Friendly - Exceeds all air pollution standards.  Electronic ignition enables you to never worry about a pilot light blowing out or leaking gas.
  • Proven Sta-Rite Technology - The Max-E-Therm Heater is the newest member in our family of advanced technology pool and spa products.  Our quality pumps and filters have been used for years to enhance the enjoyment of pools and spas nation wide.
  • Warranty - 2 years parts & labor

Product Specifications

400,000 BTU
Heat Exchanger:
Special Feature:
Low NOx Emission

?     Asked on 3/29/2008by Guest

Is the sta-rite heater Max E Therm low NOx rated for Texas?

A  Answered on 3/29/2008 by InyoPools Product Specialist Patrick P.

Yes the Sta Rite Max E Therm heaters are LoNox rated for Texas and California.

?     Asked on 1/16/2012by Guest

Will a gas heater operate at the low speed of a dual speed motor?

A  Answered on 1/16/2012 by InyoPools Product Specialist Patrick P.

Probably not - Most gas heater will shut off at low GPM levels (20-40) to keep the heater cores from overheating - 20 for 200 BTUs, 40 for 400 BTUs. Depending on your pool system you might get these GPM levels at the low speed but generally these heaters must be run at the motor's high speed.

?     Asked on 5/18/2015by Inyo Visitor

What is the Conversion from natural to propane?

A  Answered on 5/18/2015 by InyoPools Product Specialist Patrick P.

Here is the Sta Rite MaxeTherm 400,000 BTU Natural Gas to Propane Conversion Kit.

?     Asked on 9/27/2015by Bart Blackledge

I am trying to hook the Max-E-Therm heater to a Jandy Aqualink controler. Need to know how to wire. Do I use 3 or 4 wire connection?

A  Answered on 10/2/2015 by InyoPools Product Specialist Lennox H.

Hi Bart, The Max-E-Therm Owner's Manual does not indicate a 4 wire connection so it will be the 3 wire connection.

?     Asked on 4/5/2016by richard redpath

I have ne of these for ten years and the exchanger is cracked well after ten years thats fine and I am sure it was a free at some point for this issue. Anyway, I want to purchase from your site as price is same everywhere join internet at $1999 but a local outfit out hear wants 3,250, are you kidding. I should be able to swap out the unit. And that is my question can you recommend an outfit out hear or is it simple. now mind ya I am quite capable and have hooked gas lines before, send email.

A  Answered on 4/5/2016 by InyoPools Product Specialist Alan M.

Hello Richard, We would recommend that the Max-E-Therm Heater 400000 BTU be installed by a licensed service technician. In the event you need to utilize the 1 year manufacturer's warranty, they may require receipt information of who it was installed by. We suggest you contact a local pool part/supply company that performs installations.


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