Heat PumpsHeat Pump System

Keeprite C5H6S19*K*AAA + F5MA5*24L*B* Heat Pump System · AHRI 217726323

Certified ratings, sizing notes, operating tips and maintenance for this 1.5-ton split-system heat pump combination.

  • SEER215.5
  • HSPF27.8
  • Cooling18,100 Btu/h
  • Heat at 5 °F8,000 Btu/h

About this heat pump system

This page documents the split-system heat pump system made up of the Keeprite C5H6S19*K*AAA outdoor unit and the F5MA5*24L*B* indoor unit — AHRI certificate 217726323.

As a matched system it is rated at 15.5 SEER2, 13.0 EER2 and 7.8 HSPF2, delivering 18,100 Btu/h of cooling (about 1.5 tons) and 18,700 Btu/h of heating at 47 °F. At 5 °F it still produces 8,000 Btu/h — 43% of its 47 °F output with a COP of 1.90.

It uses a single-stage compressor that runs at full capacity whenever it operates — simple and robust, but less efficient at part load than multi-stage designs.

Specifications

Keeprite C5H6S19*K*AAA AHRI 217726323 ratings
BrandKeeprite
Outdoor unit modelC5H6S19*K*AAA*
Indoor unit modelF5MA5*24L*B*
AHRI reference number217726323
SEER215.5
EER213.0
HSPF27.8
Cooling capacity18,100 Btu/h
Heating capacity at 47 °F18,700 Btu/h
Heating capacity at 17 °F10,500 Btu/h
Heating capacity at 5 °F8,000 Btu/h
COP at 5 °F1.90
Compressor stagingSingle stage
RefrigerantR-454B (GWP:470 | Lower GWP)
ENERGY STAR cold climateNo
Meets peak cooling (EER2) requirementYes
Connected capabilityNo
ENERGY STAR Most EfficientNo

How it compares with other C5H6S19*K*AAA matches

The C5H6S19*K*AAA has 76 certified matches. This one's 15.5 SEER2 is higher than 3 of them (4%). The matches with the closest efficiency are listed below.

Other matches for C5H6S19*K*AAA
AHRI ref.Indoor unitSEER2EER2HSPF2Cooling Btu/h
217721732EA*5X19M17A*with furnace *95MSU0601716A*15.512.57.819,100
217721748EA*5X19M17A*+WALLCONwith furnace *96CTN0601714B*15.513.08.019,100
217721772EA*5X19M17A*+WALLCONwith furnace *97CTN0801716A*15.513.08.019,100
217721562EA*5X19M17A*with furnace *80VTL0701716B*15.513.08.019,200
217721570EA*5X19M17A*+WALLCONwith furnace *95CSU0601716B*15.512.57.819,000
217721578EA*5X19M17A*+WALLCONwith furnace *97CMN0601714B*15.513.08.019,000
217721586EA*5X19M17A*+WALLCONwith furnace *97CMN0801714B*15.513.08.019,000
217721610EA*5X19M17A*with furnace *92MSN0601412A*15.513.08.019,000
217721676EA*5X19M17A*with furnace *96MSN0801716A*15.513.08.019,200
217721708EA*5X19M17A*with furnace *96VSN0601716B*15.513.08.019,000
217721716EA*5X19M17A*with furnace *96VSN0801716B*15.513.08.019,000
217721659EA*5X19M17A*with furnace *96MSN0601412A*15.513.08.019,000

Safety information

  • Installation, refrigerant charging and electrical connection must be performed by a licensed HVAC contractor in accordance with local codes and the manufacturer's installation instructions. Many jurisdictions require a permit and inspection.
  • Turn off power at the outdoor disconnect and at the main panel before opening any service panel. Capacitors can hold a dangerous charge after power is removed.
  • Keep children and pets away from the outdoor unit; never insert objects through the fan guard.
  • Do not operate the system with panels or the fan guard removed.
  • If a gas furnace provides backup heat, make sure carbon monoxide alarms are installed on every level of the home and near sleeping areas.

Installation and sizing

Proper installation matters more than any rating on the label: field studies show that incorrect charge, poor airflow and leaky ducts can cut real-world efficiency by 30% or more. Use the checklist below when reviewing quotes for the Keeprite C5H6S19*K*AAA.

  1. Load calculation

    Insist on a room-by-room heat-loss and heat-gain calculation (ACCA Manual J) before choosing a size. Oversized heat pumps short-cycle, dehumidify poorly and wear out sooner; rule-of-thumb sizing by square footage is unreliable.

  2. Verify the matched system

    Confirm the outdoor unit, indoor coil or air handler (and furnace, if any) match an AHRI certificate. Mismatched components can lower efficiency well below the published ratings and may void rebates.

  3. Outdoor unit placement

    Set the condenser on a level pad raised above expected snow depth, with at least 12–24 in. of clearance around the coil and 5 ft above the fan. Avoid spots under roof drip lines where ice can fall onto the unit.

  4. Ductwork and airflow

    Have the contractor measure static pressure and set blower airflow (typically 350–450 CFM per ton). Leaky or undersized ducts are the most common reason a new system underperforms.

  5. Line set and charge

    The refrigerant line set should be pressure-tested, evacuated to 500 microns or lower and charged by weight and verified by subcooling or superheat as the manufacturer specifies.

  6. Commissioning

    Ask for a commissioning report showing airflow, refrigerant charge readings, thermostat configuration (including auxiliary-heat lockout) and a test of defrost operation.

Using your heat pump

Thermostat settings

Pick a comfortable setpoint and leave it. Heat pumps are most efficient when they hold a steady temperature; deep night setbacks in heating mode can trigger expensive auxiliary (strip) heat during recovery. If you use setbacks, limit them to 2–3 °F or use a thermostat with adaptive recovery designed for heat pumps.

Heating mode and defrost

In cold, damp weather frost builds up on the outdoor coil. The unit periodically reverses into a defrost cycle for a few minutes — you may see steam rising from the outdoor unit and hear a whoosh when the reversing valve shifts. This is normal.

Heating output drops as outdoor temperature falls. Below the system's balance point a backup heat source (electric strips or a furnace) supplements the heat pump; your installer should set the thermostat so backup heat runs only when needed.

Cooling and dehumidification

For better humidity control in summer, use the "Auto" fan setting rather than "On" so moisture collected on the indoor coil can drain away instead of re-evaporating into the house.

Care and maintenance

WhenWhat to do
Every 1–3 monthsCheck the air filter and replace it when dirty (1 in. filters usually monthly to quarterly; 4–5 in. media filters every 6–12 months).
Monthly in seasonKeep 2 ft clear around the outdoor unit: remove leaves, grass clippings, snow and ice. Never cover the unit while it is in use.
Each springGently hose the outdoor coil from the inside out with power off; straighten bent fins with a fin comb.
Each fallConfirm the condensate drain is clear and the outdoor unit is level and not sinking into the ground.
Every yearSchedule professional maintenance: electrical connections, capacitor test, refrigerant charge check, coil cleaning, blower and drain service, and a defrost test.

Troubleshooting

ProblemPossible causeWhat to try
No heating or coolingThermostat in wrong mode; tripped breaker or blown fuse; outdoor disconnect off.Check mode and setpoint; reset the breaker once; confirm both indoor and outdoor disconnects are on. If it trips again, call a technician.
Steam from the outdoor unit in winterNormal defrost cycle.No action needed; defrost typically lasts 2–10 minutes.
Outdoor unit covered in iceDefrost control or sensor fault; low refrigerant; blocked airflow; gutter dripping on unit.Clear snow and debris; redirect dripping water. If the coil stays encased in ice for hours, switch to emergency heat and call for service.
Air from vents feels lukewarm in heatingHeat pumps deliver air around 90–100 °F, cooler than a furnace.Normal. Check that the house is reaching setpoint rather than judging by air temperature.
High electric bills in winterAuxiliary strip heat running too often; deep setbacks; dirty filter.Reduce setbacks; ask your contractor to set an aux-heat lockout; replace the filter.
Short cyclingOversized system; thermostat near a supply register; refrigerant or control issue.Relocate the thermostat if needed; have the contractor verify sizing and charge.
Water dripping indoorsClogged condensate drain or pump; dirty coil; frozen evaporator.Turn the system off and clear the drain line; if ice is visible on the coil, check the filter and airflow before restarting.
Unusual noises (grinding, squealing)Fan motor bearings; debris in the fan; loose panel.Turn the system off and call a technician — continued operation can damage the compressor or motor.

Energy use and running costs

Assuming 1,000 full-load cooling hours per year (typical of a moderate U.S. climate), this system would use roughly 1,168 kWh for cooling — about $199 at $0.17/kWh.

For heating, 1,500 full-load hours at 7.8 HSPF2 works out to about 3,596 kWh, or $611 per year, excluding any auxiliary heat. The same heat from an 80% AFUE gas furnace would cost about $526 at $1.50/therm.

Your actual cost depends on climate, home insulation, thermostat habits and local utility rates. Use these figures to compare models rather than as a bill forecast.

Frequently asked questions

What is the SEER2 rating of AHRI 217726323?

This Keeprite C5H6S19*K*AAA + F5MA5*24L*B* system is rated at 15.5 SEER2, 13.0 EER2 and 7.8 HSPF2.

How many tons is this Keeprite heat pump system?

Its rated cooling capacity is 18,100 Btu/h, which is about 1.5 tons (12,000 Btu/h per ton).

How well does this system heat in very cold weather?

It is rated for 8,000 Btu/h at 5 °F with a COP of 1.90, meaning it delivers about 1.9 units of heat per unit of electricity. It does not meet the ENERGY STAR cold-climate criteria, so plan for backup heat in cold regions.

What refrigerant does this system use?

R-454B (GWP:470 | Lower GWP).

Can I use a different indoor unit with this outdoor unit?

Yes, but the ratings on this page apply only to this exact AHRI-certified combination. The C5H6S19*K*AAA has other certified matches listed on its main page, each with its own ratings.

Sources and disclaimer

Specifications on this page come from the ENERGY STAR certified heat pumps dataset published by the U.S. Environmental Protection Agency (record certified July 15, 2026), retrieved October 7, 2026. The AHRI reference number identifies the certified combination; verify it in the AHRI Directory of Certified Product Performance before purchase.

The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with Keeprite. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact Keeprite or an authorized service provider for warranty repairs and replacement parts.

Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.