Best Low NOx Pool Heaters

Last updated: October 31, 2026

Certified low NOx heaters, required in California and some other air districts.

Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.

Best Low NOx Pool Heaters: Under 250,000 BTU (Under 250,000 BTU)

  1. Sta-Rite Max-E-Therm 200
    #1 of 53.3Full review

    A Pentair built heater for owners on Pentair automation who want low NOx and high efficiency; compare prices with the MasterTemp first.

    Amazon $3,650
    $3,650
    200,000 BTU/h84%1 year
  2. Hayward H-Series H200FD
    #2 of 53.2Full review

    A low NOx, salt tolerant spa or small pool heater for owners who buy online and can live with a short warranty.

    Amazon $3,699
    $3,699
    199,900 BTU/h83%1 year
  3. Pentair MasterTemp 125
    #3 of 52.6Full review

    A compact, light heater for spas and above-ground pools, best for owners with Pentair automation.

    Amazon $2,098
    $2,098
    125,000 BTU/h82%1 year
  4. Hayward H-Series H150FD
    #4 of 52.6Full review

    A low NOx, salt tolerant spa or small pool heater for owners who buy online and can live with a short warranty.

    Amazon $2,999
    $2,999
    150,000 BTU/h82.7%1 year
  5. Hayward H-Series H135FD
    #5 of 52.6Full review

    An affordable heater for above-ground pools and spas where a short warranty and outdoor only installation are acceptable.

    Amazon $2,399
    $2,399
    135,000 BTU/h82%1 year

Best Low NOx Pool Heaters: 250,000 BTU and up (250,000 BTU and Up)

  1. Raypak AVIA 404A
    #1 of 74.4Full review

    The best rounded in-ground pool heater here for most owners: efficient, low NOx and app controlled with a longer warranty, if bought from an authorized dealer.

    Amazon $4,420.27
    $4,420.27
    399,000 BTU/h84%3 years
  2. Pentair MasterTemp 400
    #2 of 73.9Full review

    A strong pick for in-ground pools already on Pentair automation, though online buyers get only a short warranty.

    Amazon $4,079
    $4,079
    400,000 BTU/h84%1 year
  3. Sta-Rite Max-E-Therm 400
    #3 of 73.7Full review

    A Pentair built heater for owners on Pentair automation who want low NOx and high efficiency; compare prices with the MasterTemp first.

    Amazon $4,499
    $4,499
    400,000 BTU/h84%1 year
  4. Hayward H-Series H400FD
    #4 of 73.5Full review

    A low NOx, salt tolerant in-ground pool heater for owners who buy online and can live with a short warranty.

    Amazon $5,099
    $5,099
    399,900 BTU/h84%1 year
  5. Raypak AVIA 264A
    #5 of 73.4Full review

    The best rounded in-ground pool heater here for most owners: efficient, low NOx and app controlled with a longer warranty, if bought from an authorized dealer.

    Amazon $3,489.52
    $3,489.52
    264,000 BTU/h84%3 years
  6. Pentair MasterTemp 250
    #6 of 72.7Full review

    A strong pick for in-ground pools already on Pentair automation, though online buyers get only a short warranty.

    Amazon $3,098
    $3,098
    250,000 BTU/h84%1 year
  7. Hayward H-Series H250FD
    #7 of 72.3Full review

    A low NOx, salt tolerant in-ground pool heater for owners who buy online and can live with a short warranty.

    Amazon $3,999
    $3,999
    250,000 BTU/h84%1 year