USA's Most Trusted MRCOOL Dealer – Free Shipping*
This part may fit other MRCOOL® models or generations. Always verify your model number before ordering.
Send us your indoor unit model number, serial number, and photos of the existing part before ordering. This helps us verify compatibility and reduce the chance of ordering the wrong replacement part.
Upgrade your MRCOOL Universal 2nd Gen central ducted system with a factory-matched Electric Heat (Emergency/Aux) Kit. This add-on installs in the air handler and provides an extra boost of electric heat when outdoor temperatures drop well below your heat pump’s rated heating range—helping maintain comfort during cold snaps.
Available sizes: 5kW • 8kW • 10kW • 15kW • 20kW
Includes: model-specific heat strip assembly with integrated circuit breaker
Cold-weather backup: Heat pumps naturally lose heating capacity as outdoor temps fall. The heat kit supplies aux/emergency heat to cover those lows.
Comfort & reliability: Smooth transitions during defrost and extreme weather.
Factory-matched fit: Designed for MRCOOL Universal 2nd Gen air handlers for correct airflow, safeties, and wiring.
Smaller air handlers → smaller kW (check your model label/manual).
Warmer/Southern climates: often optional; a smaller kW is typically sufficient for rare cold snaps.
Colder/Northern climates: recommended; choose a larger kW where supply power and air handler size allow.
Tip: Match heat-kit kW to your air handler model and available electrical capacity. When in doubt, contact us and we’ll confirm the best fit.
Circuit breaker included for the kit (model-specific)
Aux/Emergency heat for sub-freezing weather
Designed for MRCOOL Universal 2nd Gen air handlers
DIY-friendly for confident installers; professional assistance recommended where required by code
For MRCOOL Universal 2nd Gen central ducted air handlers only.
Heat kits are model-specific. Please verify your exact air-handler model number and electrical specs before ordering. We’re happy to help you confirm.
Electric heat strip assembly (size selected)
Integrated circuit breaker (factory-matched)
Mounting hardware (varies by model)
Install/connection guide
Turn off power at the disconnect/breaker before service.
Use proper wire gauge and overcurrent protection per the air handler/kit nameplate and local code.
Ensure airflow and duct static pressure meet the air handler’s requirements when running electric heat.
A licensed electrician/HVAC professional may be required by local code.
Need help choosing 5kW, 8kW, 10kW, 15kW, or 20kW?
Send us your air-handler model number, climate/zip code, and available breaker size—we’ll recommend the right kit for your system.
| Known Compatible Models / Series |
|
|---|---|
| Compatibility Notice | This part may fit other MRCOOL® models and generations. Compatibility outside the listed models is not guaranteed without verification. |
| Brand | Aux/Emergency Heat |
|---|---|
| MRCOOL® Part Number | UHK05 |
No common symptom information has been added for this part type yet.
This replacement part should be installed by a qualified technician or a capable installer familiar with mini split service procedures. Always disconnect power before servicing HVAC equipment.
No Q&A content has been added for this replacement part yet.
HEAT STRIP SIZING & PERFORMANCE
The correct electric heat strip size depends on more than air handler tonnage. Climate, home insulation, electrical capacity, system design, and heating demands all affect which heat kit is appropriate for your HVAC system.
Homes in colder climates often require larger auxiliary heat capacity because heat pumps lose efficiency as outdoor temperatures fall
Northern climates may benefit from larger backup heat kits than mild-weather regions.
Heat strips draw significant electrical current. Your panel capacity, breaker size, and wiring must support the selected heat kit.
Always verify electrical requirements before upgrading to a larger kW heat strip.
Poor insulation increases heat loss and can increase demand on both the heat pump and electric backup heat system.
Improving insulation may reduce heating costs more than increasing heat strip size.
Larger homes generally require more heating capacity, but square footage alone should not determine heat strip selection.
Heat load calculations are more accurate than simple square-foot estimates.
Drafty homes, large entryways, and poorly sealed structures can dramatically increase heating demand.
Air sealing improvements can significantly improve HVAC performance.
Heat strips are not universal. Each air handler has specific approved heat kit sizes and electrical configurations.
Always verify your air handler model number before ordering a heat strip.
Heat strips provide auxiliary and emergency heat when additional heating capacity is needed. Choosing the correct heat kit requires verifying air handler compatibility, electrical requirements, climate conditions, and manufacturer specifications.