Best Electric Heat Kits for MRCOOL Air Handlers: 2026 Buying Guide
Published by HVACProSales Team on Mar 26th 2026
Best Electric Heat Kits for MRCOOL Air Handlers: 2026 Buying Guide
As the HVAC industry moves toward higher efficiency and greener refrigerants, homeowners and contractors alike are looking for reliable supplemental heating solutions. For those utilizing MRCOOL air handlers, the addition of an electric heat kit (often called a "heat strip") is the most effective way to ensure consistent comfort when outdoor temperatures drop below the heat pump's optimal operating range. This guide provides a deep dive into the best electric heat kits for MRCOOL air handlers in 2026, covering compatibility, technical specifications, and professional installation insights.
🏆 Top Picks at a Glance
- Check the thermostat settings and battery first
- Inspect the air filter — replace if dirty or clogged
- Check the circuit breaker and reset if tripped
- Inspect the capacitor and contactor for visible damage
- Verify refrigerant pressure is within spec using manifold gauges
- Call a licensed technician if the fault is not identified
What is an Electric Heat Kit and Why Do You Need One?
An electric heat kit is a modular heating accessory designed to be installed directly into the blower section of an air handler. It consists of resistive heating elements that provide "emergency" or "supplemental" heat.
"A heat strip kit is an electric heating accessory commonly used in HVAC systems to provide supplemental or backup heat... these kits activate when outdoor temperatures are too low for the heat pump to operate efficiently." [1]
For MRCOOL systems, these kits are essential for two primary reasons:
1. Defrost Mode Support: During winter, heat pumps occasionally enter a defrost cycle to melt ice on the outdoor coil. During this time, the system essentially runs in cooling mode. The heat kit prevents cold air from blowing into your home by tempering the air.
2. Extreme Cold Performance: While MRCOOL Hyper Heat systems can operate in temperatures as low as -22°F, their heating capacity naturally decreases as it gets colder. A heat kit provides the extra BTUs needed to maintain your thermostat's set point.
Top MRCOOL Electric Heat Kits by Series
Choosing the right heat kit depends entirely on which MRCOOL air handler series you have installed. Using an incompatible kit can lead to electrical failure or voided warranties.
1. MRCOOL Central Ducted Series (CENTRALHK)
The Central Ducted series is the workhorse of the MRCOOL lineup. The CENTRALHK kits are specifically engineered for these high-static air handlers.
| Model | Capacity | Compatibility | Max Breaker |
|---|---|---|---|
| CENTRALHK05 | 5kW | 12k - 36k BTU | 30A |
| CENTRALHK10 | 10kW | 18k - 60k BTU | 60A |
| CENTRALHK15 | 15kW | 24k - 60k BTU | 30A (Dual) |
| CENTRALHK20 | 20kW | 36k - 60k BTU | 60A (Dual) |
Pro Insight: For 15kW and 20kW kits, you typically need a dual-circuit electrical setup. Always verify your home's electrical panel capacity before purchasing these larger units.
2. MRCOOL Universal Series (MHK-U)
The Universal Series is famous for its "quick-connect" capabilities and extreme cold weather performance. The MHK-U series heat kits are designed with nickel-chromium elements for longevity. [2]
- MHK05U (5kW): Ideal for 2-ton and 3-ton systems in milder climates.
- MHK10U (10kW): The standard for 3-ton to 5-ton systems, providing roughly 34,000 BTUs of backup heat.
- MHK15U (15kW): Recommended for 4-ton and 5-ton systems in northern climates.
3. MRCOOL VersaPro Series (MVPHK)
The VersaPro series represents the latest in MRCOOL's mini split refrigerant types refrigerant technology. These kits are optimized for the 2nd Gen Hyper Heat systems. [1]
| Model | Size | MCA (230V) | MOP (230V) |
|---|---|---|---|
| MVPHK05 | 5kW | 27.0A | 30A |
| MVPHK08 | 8kW | 42.0A | 45A |
| MVPH10 | 10kW | 53.0A | 60A |
Technical Comparison: 5kW vs. 10kW vs. 15kW
When selecting a heat kit, the "bigger is better" philosophy doesn't always apply. You must balance your heating needs with your electrical infrastructure.
The 5kW Option (Small Homes & Temperate Climates)
A 5kW kit provides approximately 17,000 BTUs. This is usually sufficient for a 1,000–1,200 sq. ft. space or as a defrost-only backup in southern states. It requires a 30A breaker and 10-gauge wire.
The 10kW Option (The "Goldilocks" Choice)
Providing ~34,000 BTUs, the 10kW kit is the most popular choice for average-sized homes. It requires a 60A breaker and 6-gauge wire, which may require a dedicated sub-panel or a significant upgrade if your current panel is full.
The 15kW+ Option (Large Homes & Extreme Cold)
For large multi-story homes or regions where temperatures stay below zero for weeks, 15kW or 20kW kits are necessary. These often require two separate circuits (e.g., a 30A and a 60A circuit) to power the multiple stages of heating elements.
Professional Installation & Safety Tips
While MRCOOL is known for its DIY-friendly mini-splits, installing a heat kit involves high-voltage electrical work.
- Breaker Sizing: Always match the breaker to the Maximum Overcurrent Protection (MOP) listed on the heat kit's nameplate. Using an undersized breaker will lead to frequent tripping. [1]
- Wire Gauge: Ensure your wiring can handle the Minimum Circuit Ampacity (MCA). For a 10kW kit, you almost always need 6 AWG copper wire.
- Airflow Configuration: Most MRCOOL heat kits are designed for multi-positional air handlers. However, you must ensure the kit is seated correctly to prevent hotspots and "burning" smells during initial startup.
"The specification may be different between different models. Refer to the indoor unit’s nameplate. Choose the cable type according to the local electrical codes and regulations." [1]
Real-World Use Case: The Minnesota Winter
Consider a homeowner in Minneapolis with a 3-ton MRCOOL Universal system. While the heat pump provides 100% capacity down to -5°F, the occasional -20°F polar vortex can overwhelm the system. By installing an MHK10U heat kit, the homeowner ensures that even if the outdoor unit shuts down, the electric strips will maintain a safe 68°F indoors, preventing frozen pipes and discomfort.
Frequently Asked Questions
Can I install a 10kW heat kit on a 15-amp circuit?
No. A 10kW heat kit requires a 60-amp breaker and heavy-duty 6-gauge wiring. Attempting to run it on a 15-amp circuit is a fire hazard and will immediately trip the breaker.
Do MRCOOL heat kits come with a circuit breaker?
Many MRCOOL heat kits, such as the Signature and VersaPro series, include a built-in circuit breaker for the unit itself, but you still need a properly sized breaker in your main electrical panel. [1]
Will adding a heat kit increase my electric bill?
Only when it is running. Electric resistive heat is 100% efficient but more expensive than heat pump operation. It is intended for supplemental use, not as the primary heat source year-round.
Recommended HVAC Parts & Tools
Conclusion
Upgrading your MRCOOL system with an electric heat kit is a smart investment for long-term comfort and safety. Whether you choose the standard CENTRALHK for a ducted system or the advanced MVPHK for a VersaPro unit, ensure you match the capacity to both your climate needs and your home's electrical limits.
For the best selection of MRCOOL compatible parts and expert advice, visit our shop or contact our technical support team.
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If you're unsure which kit is right for your specific air handler model, our team is here to help.
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* Phone: 1-866-330-1709