What is the SEER2 rating of the Heil H5H6S31*K*AAA?

The Heil H5H6S31*K*AAA is rated at up to 16.0 SEER2 and 13.0 EER2 for cooling and up to 8.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 114 certified matchups SEER2 ranges from 15.2-16.0.

Is the Heil H5H6S31*K*AAA good for cold climates?

It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 2.5-ton model.

How much does the Heil H5H6S31*K*AAA cost to run per year?

At its rated efficiency it costs about $859-$2,393 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,072 in Phoenix and $2,009 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

Is the Heil H5H6S31*K*AAA the same as the Comfortmaker C5H6S31*K*AAA?

Yes, as far as the certified ratings go. ENERGY STAR lists both model numbers with identical efficiency, capacity and matchups, which means the same outdoor unit sold under a different brand or with a minor variant code (voltage, colour or region). The full list is on this page.

Which indoor units work with the Heil H5H6S31*K*AAA?

ENERGY STAR lists 114 certified combinations for this outdoor unit. The highest-rated ones use FHMA5*42L*C, FM(C,U)5Z30**AL, FM(C,U)5Z36**AL.

2.5-ton central heat pump · MAINLINE 16 SEER2 HP

Heil H5H6S31KAAA

Below average cooling and heating efficiency for a 2.5-ton central heat pump, but not rated for cold climates.

Ranks #158 of 199 2.5 ton central heat pumps for cooling efficiency, and costs about $992 a year to run in a mixed climate like Atlanta.

SEER2: 16.0 Cooling efficiency over a season
Below average · beats 26%
HSPF2: 8.0 Heating efficiency over a season
Below average · beats 12%
EER2: 13.0 Cooling efficiency on a 95°F day
Very good · beats 89%
Heat at 5°F: 14,000 BTU/h45% of its 47°F output
Average · beats 51%

A good fit if…

You want a choice of indoor units - 114 certified pairings.

Think twice if…

You often see nights below 0°F - it is not cold-climate certified.
Cooling cost matters most - its SEER2 is below average for central heat pumps.
You mainly need heat - its HSPF2 is below average for central heat pumps.
Comfort and noise matter - a single-stage compressor runs only full-on or off.

Calculate my running cost

Details

Specifications2.5 ton, R-454B

General
Brand	Heil
Also sold as	Airquest, Arcoaire, Comfortmaker, Day & Night, Keeprite
Outdoor unit model	H5H6S31KAAA
Series	MAINLINE 16 SEER2 HP
Type	Central heat pump
Nominal size	2.5 ton
CompressorVariable-speed units run longer at low power	Single stage
Refrigerant	R-454B
Connected (smart) capable	No
On the market since	July 31, 2025
Last certified	July 17, 2026
Cooling
SEER2Seasonal efficiency, higher is better	16.0 (range 15.2-16.0)
EER2Efficiency at 95°F outdoors	11.7-13.0
Cooling capacity	27,400-29,400 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	7.8-8.0
Capacity at 47°F	29,200-30,600 BTU/h
Capacity at 17°F	17,300-18,200 BTU/h
Capacity at 5°F	13,100-14,000 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	2.00-2.06
ENERGY STAR cold climate	No

Heating output as it gets colder45% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with FHMA5*42L*C at the standard test temperatures, in BTU/h:

Certified matchups114 indoor units

The same outdoor unit scores differently with each indoor unit and furnace. The 60 highest-rated of 114 are shown. Ask your installer for the AHRI reference number of the exact system you are quoted.

Indoor unit	Furnace	SEER2	EER2	HSPF2	Heat @5°F	AHRI ref.
FHMA542LC	-	16.0	13.0	8.0	13,400	217687287
FM(C,U)5Z30**AL	-	16.0	12.5	8.0	13,400	217687290
FM(C,U)5Z36**AL	-	16.0	12.5	8.0	13,400	217687291
FMA5X30**AL	-	16.0	13.0	8.0	13,700	217687294
FMA5X36**AL	-	16.0	13.0	8.0	13,700	217687295
F5MA542LC	-	16.0	13.0	8.0	13,400	217721447
FHMA542LC	-	16.0	13.0	8.0	13,400	217721448
F5MA542LC	-	16.0	13.0	8.0	13,400	217721449
FHMA542LC	-	16.0	13.0	8.0	13,400	217721450
F5MA542LC	-	16.0	13.0	8.0	13,400	217721451
FM(C,U)5Z30**AL	-	16.0	12.5	8.0	13,400	217721476
FM(C,U)5Z30**AL	-	16.0	12.5	8.0	13,400	217721477
FM(C,U)5Z36**AL	-	16.0	12.5	8.0	13,400	217721483
FM(C,U)5Z36**AL	-	16.0	12.5	8.0	13,400	217721484
FMA5X30**AL	-	16.0	13.0	8.0	13,700	217721504
FMA5X30**AL	-	16.0	13.0	8.0	13,700	217721505
FMA5X36**AL	-	16.0	13.0	8.0	13,700	217721511
FMA5X36**AL	-	16.0	13.0	8.0	13,700	217721512
EA*5X37M21A	80MSU0601716A	15.5	12.0	8.0	14,000	217717313
EA*5X37M21A	80MSU0601716A	15.5	12.0	8.0	14,000	217717314
EA*5X37M21A	80MSU0601716A	15.5	12.0	8.0	14,000	217717315
EA*5X37M21A	80MSU0802120A	15.5	12.5	8.0	14,000	217717321
EA*5X37M21A	80MSU0802120A	15.5	12.5	8.0	14,000	217717322
EA*5X37M21A	80MSU0802120A	15.5	12.5	8.0	14,000	217717323
EA*5X37M21A	80MS(N,L)0902120A	15.5	12.5	8.0	14,000	217717257
EA*5X37M21A	80MS(N,L)0902120A	15.5	12.5	8.0	14,000	217717258
EA*5X37M21A	80MS(N,L)0902120A	15.5	12.5	8.0	14,000	217717259
EA*5X37M21A	80MS(N,L)1102120A	15.5	12.5	8.0	14,000	217717266
EA*5X37M21A	80MS(N,L)1102120A	15.5	12.5	8.0	14,000	217717265
EA*5X37M21A	80MS(N,L)1102120A	15.5	12.5	8.0	14,000	217717267
EA*5X37M21A	80VSL1102122B	15.5	12.5	8.0	14,000	217717297
EA*5X37M21A	80VSL1102122B	15.5	12.5	8.0	14,000	217717298
EA*5X37M21A	80VSL1102122B	15.5	12.5	8.0	14,000	217717299
EA5X37M21A+WALLCON	80CSU0401712B	15.5	12.0	8.0	13,900	217717185
EA5X37M21A+WALLCON	80CSU0401712B	15.5	12.0	8.0	13,900	217717186
EA5X37M21A+WALLCON	80CSU0401712B	15.5	12.0	8.0	13,900	217717187
EA*5X37M21A	92MSN0802120A	15.5	12.5	8.0	14,000	217717489
EA*5X37M21A	92MSN0802120A	15.5	12.5	8.0	14,000	217717490
EA*5X37M21A	92MSN0802120A	15.5	12.5	8.0	14,000	217717491
EA*5X37M21A	92MSN1002120A	15.5	12.5	8.0	14,000	217717497
EA*5X37M21A	92MSN1002120A	15.5	12.5	8.0	14,000	217717498
EA*5X37M21A	92MSN1002120A	15.5	12.5	8.0	14,000	217717499
EA*5X37M21A	92MSN1002122A	15.5	12.5	8.0	14,000	217717505
EA*5X37M21A	92MSN1002122A	15.5	12.5	8.0	14,000	217717506
EA*5X37M21A	92MSN1002122A	15.5	12.5	8.0	14,000	217717507
EA5X37M21A+WALLCON	80CSU0802120B	15.5	12.5	8.0	14,000	217717201
EA5X37M21A+WALLCON	80CSU0802120B	15.5	12.5	8.0	14,000	217717202
EA5X37M21A+WALLCON	80CSU0802120B	15.5	12.5	8.0	14,000	217717203
EA*5X37M21A	95MSU1002122A	15.5	12.0	8.0	14,000	217717648
EA*5X37M21A	95MSU1002122A	15.5	12.0	8.0	14,000	217717647
EA*5X37M21A	95MSU1002122A	15.5	12.0	8.0	14,000	217717649
EA*5X43M21A	96VTN1002122B	15.5	13.0	8.0	14,000	217718409
EA*5X43M21A	96VTN1002122B	15.5	13.0	8.0	14,000	217718410
EA*5X43M21A	96VTN1002122B	15.5	13.0	8.0	14,000	217718411
EA*5X37M21A	96VTN1002122B	15.5	12.5	8.0	14,000	217717743
EA*5X37M21A	96VTN1002122B	15.5	12.5	8.0	14,000	217717744
EA*5X37M21A	96VTN1002122B	15.5	12.5	8.0	14,000	217717745
EA*5X37M21A	97VTN1002122A	15.5	12.5	8.0	14,000	217717783
EA*5X37M21A	97VTN1002122A	15.5	12.5	8.0	14,000	217717784
EA*5X37M21A	97VTN1002122A	15.5	12.5	8.0	14,000	217717785

Same unit, other model numbers1

These model numbers have exactly the same certified ratings and matchups as the Heil H5H6S31*K*AAA: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

Comfortmaker C5H6S31*K*AAA

Yearly running cost in 10 large cities$859-$2,393

Phoenix, AZ$1,072/yr
Miami, FL$859/yr
Houston, TX$962/yr
Atlanta, GA$992/yr
Los Angeles, CA$969/yr
New York, NY$2,393/yr
Chicago, IL$1,947/yr
Denver, CO$1,622/yr
Seattle, WA$1,000/yr
Minneapolis, MN$2,009/yr

At each state's average electricity price and the city's typical heating and cooling hours.

Questions6

What is the SEER2 rating of the Heil H5H6S31*K*AAA?: The Heil H5H6S31*K*AAA is rated at up to 16.0 SEER2 and 13.0 EER2 for cooling and up to 8.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 114 certified matchups SEER2 ranges from 15.2-16.0.
Is the Heil H5H6S31*K*AAA good for cold climates?: It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 2.5-ton model.
How much does the Heil H5H6S31*K*AAA cost to run per year?: At its rated efficiency it costs about $859-$2,393 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,072 in Phoenix and $2,009 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Is the Heil H5H6S31*K*AAA the same as the Comfortmaker C5H6S31*K*AAA?: Yes, as far as the certified ratings go. ENERGY STAR lists both model numbers with identical efficiency, capacity and matchups, which means the same outdoor unit sold under a different brand or with a minor variant code (voltage, colour or region). The full list is on this page.
Which indoor units work with the Heil H5H6S31*K*AAA?: ENERGY STAR lists 114 certified combinations for this outdoor unit. The highest-rated ones use FHMA5*42L*C, FM(C,U)5Z30**AL, FM(C,U)5Z36**AL.
What refrigerant does the Heil H5H6S31*K*AAA use?: It uses R-454B.

Running cost and savings

Pre-filled with this model. Pick your city and what you heat with today; everything else is optional.

Heat pump $1,071/yrYou save $458/yrSee details ↓

1. Where you live

StateCityElectricity ¢ per kWh

Adjust heating and cooling hours

Filled in from your city's climate. Change them if you run the system much more or less than usual.

Cooling hours full-load hours per yearHeating hours full-load hours per year

2. The heat pump Heil H5H6S31*K*AAA

Find a model (fills in the ratings below)

SEER2 cooling efficiencyHSPF2 heating efficiencyCooling capacity BTU/hHeating capacity BTU/h

3. What it replaces

Current heatingFurnace efficiency (AFUE %)Gas price, $/thermCurrent coolingOld AC rating SEER2 (10 ≈ 15+ years old)

4. Price replace the example with your quote

Installed price, $Rebates and incentives, $ utility, state

Heat pump, per year: $1,071
Current system, per year: $1,529
You save per year: $458
Payback: 24.0 years
Net after 10 years: -$6,423

Cooling $642Heating $428Electricity used: 6,693 kWhSaved vs. a minimum-efficiency heat pump: $105

Estimates use the unit's rated SEER2 and HSPF2, full-load hours derived from NOAA 1991-2020 degree days, average residential electricity prices from the U.S. EIA (12 months to July 2026) and fuel prices from EIA (2025 for natural gas, week of 2026-10-05 for propane and heating oil). Very cold days that need backup heat are not modelled. Federal minimum for comparison: 14.3 SEER2 / 7.5 HSPF2.

Similar 2.5 ton models

Kenmore R5H5S31*K*AAA16.0 SEER2 · 8.0 HSPF2
Grandaire W5H5S31*K*AAA16.0 SEER2 · 8.0 HSPF2
Tempstar T5H6S31*K*AAA16.0 SEER2 · 8.0 HSPF2
Carrier 27SPA631A**3016.0 SEER2 · 8.0 HSPF2
WeatherMaker PH5SAN531**AB16.0 SEER2 · 8.0 HSPF2
Bryant PH5SAN531**AA16.0 SEER2 · 8.0 HSPF2
Hisense AUWR-36U3SA · cold climate15.5 SEER2 · 9.4 HSPF2
Bryant GH5SAN531**AA16.0 SEER2 · 8.0 HSPF2

See all 199 2.5 ton central heat pumps, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of July 17, 2026. How we use the data.