How Much Does Emergency Heat on a Heat Pump Cost in 2026?

CostInsightHub Editorial Team Updated: May 25, 2026 7 min read

If your heat pump has suddenly switched to emergency heat mode, you may be wondering how much that red indicator light is going to cost you. The emergency heat on heat pump cost can add up quickly—especially during a cold snap. Understanding what drives these expenses helps you make informed decisions about your HVAC system and avoid sticker shock when the utility bill arrives.

What Is Emergency Heat on a Heat Pump?

Emergency heat—sometimes labeled as "EM heat" on your thermostat—is a backup heating mode that bypasses the heat pump's normal operation. Instead of extracting warmth from outdoor air, it activates electric resistance strips inside the indoor air handler. These strips work like a giant toaster, generating heat directly but consuming significantly more electricity than the heat pump's normal compressor-based heating cycle.

This mode is designed for true emergencies: when the outdoor unit fails, gets damaged by ice, or when temperatures drop so low that the heat pump can no longer extract enough warmth from the outside air. It is not meant for daily use or for warming up a cold house faster—a common misconception that leads to unnecessarily high bills.

How Much Does Emergency Heat Cost Per Hour?

The hourly expense depends on two main factors: the size (kilowatt rating) of your electric resistance strips and your local electricity rate. Most residential heat pump systems have auxiliary heat strips rated between 10 kW and 15 kW. At the national average electricity price of roughly $0.15 per kilowatt-hour, here is how the math breaks down:

• 10 kW system: 10 kW × $0.15/kWh = $1.50 per hour
• 12.5 kW system: 12.5 kW × $0.15/kWh = $1.88 per hour
• 15 kW system: 15 kW × $0.15/kWh = $2.25 per hour

If emergency heat runs for 10 hours a day during a cold spell, that translates to $15.00 to $22.50 daily—or roughly $450 to $675 over a 30-day billing cycle for the emergency heat portion alone. By comparison, a heat pump in normal heating mode might use only 3–4 kW per hour, making it two to four times more efficient than the backup strips.

Monthly Emergency Heat Costs by US City

Electricity rates vary widely across the United States, which means the monthly impact of running emergency heat looks different depending on where you live. The table below compares estimated monthly costs for a 15 kW system running 8 hours per day across several major cities, based on local average residential electricity rates in 2026.

Estimates based on a 15 kW heat strip running 8 hours per day. Actual costs depend on system size, thermostat settings, and weather conditions.

Auxiliary Heat vs. Emergency Heat: What's the Cost Difference?

Many homeowners confuse auxiliary heat (often displayed as "AUX heat") with emergency heat. While both use the same electric resistance strips, the key difference lies in how they are activated:

• Auxiliary heat kicks in automatically when the heat pump cannot keep up with the thermostat setting—typically a 2–3°F gap. It supplements the heat pump, which continues to run alongside the strips. This is normal, short-term operation during very cold weather.
• Emergency heat is manually selected by the homeowner or triggered by a system fault. It locks out the heat pump entirely and runs the strips exclusively. This mode is far more expensive because the efficient heat pump compressor is completely shut off.

From a cost perspective, auxiliary heat mode is generally less expensive because the heat pump still contributes some efficiency. Emergency heat mode places the full heating burden on the resistance strips, maximizing electricity consumption. If you see "AUX" on your thermostat during a cold morning, that is usually normal. If you manually switch to "EM heat," expect a noticeably higher bill.

Why Is Emergency Heat So Expensive?

The short answer is physics. A heat pump in normal operation moves heat rather than creating it—it can deliver 2 to 4 units of heat for every unit of electricity consumed, achieving what is called a Coefficient of Performance (COP) of 2.0 to 4.0. Electric resistance strips, by contrast, have a COP of exactly 1.0: one unit of electricity produces one unit of heat. No multiplier effect, no efficiency gain.

This fundamental difference means emergency heat consumes two to four times more electricity to produce the same amount of warmth. When outdoor temperatures hover near freezing, a properly functioning heat pump remains the far more economical choice—even if it runs continuously. Reserve the emergency setting for actual equipment failures or damage, not for cold-weather comfort.

Practical Tips to Reduce Emergency Heat Costs

While emergency heat is sometimes unavoidable, there are several strategies to minimize how much it impacts your wallet:

1. Schedule annual heat pump maintenance. A well-maintained system is less likely to fail during winter. Clean coils, proper refrigerant levels, and inspected electrical connections reduce the odds of needing emergency mode. Many installer pricing packages include a seasonal tune-up at a reasonable rate.
2. Seal air leaks and improve insulation. Reducing heat loss means the heat pump runs less overall, decreasing the chance it will fall behind and trigger auxiliary or emergency modes. Focus on attic insulation, door weatherstripping, and window sealing.
3. Use a programmable thermostat wisely. Avoid large temperature setbacks (more than 4–5°F) during cold weather. A deep setback can force the system into auxiliary heat when recovering, erasing any savings from lowering the temperature overnight.
4. Know when emergency heat is actually necessary. If your outdoor unit is covered in ice, physically damaged, or making unusual noises, emergency heat is justified. If the house simply feels chilly, let the heat pump do its job—even if it runs longer cycles.
5. Monitor your electricity usage. Many utility companies now offer online dashboards showing daily consumption. A sudden spike can alert you that emergency heat has been running more than expected, prompting a system check before the bill arrives.

Common Mistakes That Drive Up Emergency Heat Bills

Even well-intentioned homeowners sometimes make costly errors when operating their heat pump systems. Here are the most frequent missteps our research has identified through contractor surveys and consumer reports:

• Switching to emergency heat to "warm up faster." This is the number-one misunderstanding. Emergency heat does not heat the home faster—it simply uses more electricity to do the same job. Let the heat pump run its normal cycle.
• Ignoring the "AUX heat" indicator for weeks. If auxiliary heat runs frequently, something may be wrong—low refrigerant, a failing compressor, or a dirty filter. Prolonged auxiliary operation quietly drives up costs and may lead to a full system breakdown.
• Cranking the thermostat up by 5–10°F at once. Large manual temperature jumps almost always trigger the auxiliary strips. Gradual adjustments keep the heat pump in its efficient operating range.
• Skipping filter changes. A clogged air filter reduces airflow, making the heat pump work harder and increasing the likelihood of auxiliary heat activation. Check filters monthly during heavy-use seasons.

Data Sources & Methodology

The cost estimates in this article are drawn from a combination of publicly available information and ongoing market research. We synthesize data from multiple authoritative sources to provide realistic pricing ranges for U.S. consumers.

• Residential electricity rate data from the U.S. Energy Information Administration (EIA) and state-level utility commissions
• Heat pump system specifications and energy consumption benchmarks published by ENERGY STAR and the U.S. Department of Energy
• Contractor pricing surveys and aggregated cost data from platforms such as Angi and HomeAdvisor
• Industry reports on HVAC system performance, repair frequency, and energy efficiency trends
• Publicly available utility rate schedules and residential energy consumption databases

All content is produced and maintained by the CostInsightHub Editorial Team for general informational purposes. Figures are estimates based on aggregated market research and should not be interpreted as guaranteed pricing for any specific provider or location.