How many amps does a heat pump use?

It depends entirely on capacity and type. A ductless mini split serving one room may need a 15- or 20-amp circuit; a central cold-climate heat pump may need 30 to 60 amps. Always follow the nameplate's minimum circuit ampacity and maximum overcurrent protection rather than a rule of thumb.

Does a heat pump replace an existing electric load?

Often yes, and it matters. If a heat pump replaces electric resistance heating or an existing AC condenser, the calculation only counts the larger of heating or cooling — so the net addition can be much smaller than the nameplate suggests, and can even be a reduction.

Can I avoid electric backup heat?

Sometimes. Cold-climate heat pumps maintain useful output at low temperatures, and a dual-fuel setup keeps an existing gas furnace as backup instead of strip heat. Both reduce or eliminate the largest electrical load in the project.

Do You Need a Panel Upgrade for a Heat Pump?

Updated 2026-08-16 · 7 min read

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Heat pumps have a reputation for forcing service upgrades. The reputation is half-earned: the heat pump itself is usually a manageable load, and the electric resistance backup heat installed alongside it frequently is not.

Separating those two is what determines whether you need an upgrade.

How many amps does a heat pump draw?

A heat pump's outdoor unit draws a moderate amount:

System	Typical circuit
Single-zone ductless mini split	15–20 A, 240 V
Multi-zone ductless	20–30 A, 240 V
Central heat pump, 2–3 ton	20–35 A, 240 V
Central heat pump, 4–5 ton	35–60 A, 240 V

Always use the nameplate, which states a minimum circuit ampacity (MCA) and a maximum overcurrent protection (MOCP). Both are enforceable under the NEC, and the MOCP is often larger than you'd calculate from running current because motor inrush needs headroom. See what size breaker do I need.

Size the equipment itself first — an oversized heat pump costs more to install, runs worse, and draws more. Use the heat pump sizing calculator or the mini split sizing calculator.

Why does backup heat need so much power?

Air handlers for central heat pumps commonly include electric resistance strip heat for very cold weather and for defrost cycles. And strip heat is enormous:

Strip heater	Amps at 240 V
5 kW	~21 A
10 kW	~42 A
15 kW	~62 A
20 kW	~83 A

A 15 kW strip heater is 62 amps — well over half of a 100-amp service by itself, and it counts in the heating load of your calculation.

This is what forces service upgrades, not the compressor. When a contractor says a heat pump needs 200 amps, ask specifically how much backup heat is in the proposal.

What is NEC 220.83 load calculation?

The NEC's dwelling load calculation counts the larger of the heating load or the cooling load — not both. A house doesn't heat and cool at the same time.

That has real consequences:

Replacing an AC condenser with a heat pump may add nothing to the cooling side, and the heating side only matters if it exceeds it.
Replacing electric resistance heating with a heat pump can be a net reduction. Baseboard heat for a whole house is far more connected load than a heat pump plus modest backup.
Adding a heat pump to a gas-heated home is where the addition is largest, because you're adding an electric heating load that didn't exist.

Run the calculation with your actual before-and-after configuration — see how to do a home electrical load calculation and the home electrical load calculator.

How do you avoid a panel upgrade for a heat pump?

1. Reduce or eliminate strip heat

The highest-leverage change available.

Cold-climate heat pumps maintain useful capacity at low outdoor temperatures, which reduces how much backup is needed — sometimes to a small heater for defrost only. Specifying a smaller strip heater, where the design supports it, can cut tens of amps out of the calculation.

Ask the HVAC contractor to justify the backup size against the design temperature rather than defaulting to the largest heater the air handler accepts. Oversized strip heat is common because it costs the contractor almost nothing and eliminates callbacks.

2. Dual fuel

Keep the existing gas furnace as backup instead of installing strip heat. A control setup runs the heat pump most of the season and switches to the furnace below a balance point.

The electrical load is then just the compressor and the blower — no strip heat at all. This is often the cheapest path in a home that already has a working furnace.

3. Ductless instead of ducted

Ductless mini splits generally have no electric backup heat and much smaller circuits. For a home without ducts, or for zoned additions, this sidesteps the problem entirely.

4. Right-size the equipment

Oversized systems draw more, cost more, and short-cycle. A Manual J-style load calculation for the house — separate from the electrical load calculation — is what produces the correct capacity. Contractors who size by square footage alone routinely oversize.