Arlington County, VA homeowners with heat pump systems that include electric resistance backup heat have a component in their air handler that most of them have never thought about — the electric strip heaters that engage when the outdoor temperature drops below the heat pump’s effective operating range and that serve as the system’s last line of defense on the coldest winter nights. These elements fail. They fail in specific ways at specific ages. And because they are only called upon during the coldest weather — when the heat pump alone is insufficient — their failure is discovered on exactly the nights when adequate heating matters most.
What Electric Strip Heaters Are and Why Arlington County Systems Have Them
Most Arlington County residential heat pump systems include one or more stages of electric resistance supplemental heat — resistance heating elements made from nichrome wire coils mounted in the air handler’s discharge air stream. When the outdoor temperature drops below the heat pump’s effective range — typically below 30 to 35°F for older systems, lower for modern cold-climate heat pumps — the thermostat activates these elements to supplement or replace the heat pump’s output. They are, in function, identical to a large electric space heater built into the air handler. They operate at exactly 100 percent efficiency — one watt in, one watt of heat out — which makes them the most expensive form of heating available but also the most reliable: no refrigerant, no compressor, no reversing valve. Just wire that gets hot when current passes through it.
How Strip Heaters Fail in Arlington County Air Handlers
Electric resistance strip heaters fail through two primary mechanisms in Arlington County’s aging heat pump systems. The first is open element failure — the nichrome wire that carries the heating current develops a break, either from mechanical fatigue from years of thermal expansion and contraction cycling or from localized overheating from restricted airflow. An open element produces less total heat output than the system was designed to provide. If one element in a two-element system opens, the system delivers 50 percent of its designed supplemental heat capacity — adequate in mild cold, inadequate during a severe cold snap. The second failure mode is the sequencer relay — the time-delay relay that stages the heating elements on progressively to prevent the electrical system from absorbing the full startup current of all elements simultaneously. Failed sequencers cause elements to fail to energize, to energize simultaneously causing circuit breaker trips, or to remain energized when they should be off.
Heating Element Failure Symptoms in Arlington County Heat Pump Systems
- Inadequate heat output on the coldest nights despite the system running continuously
- A breaker in the electrical panel that trips specifically during cold weather — the sequencer failing and allowing elements to energize simultaneously
- Supply air that feels merely warm rather than hot when the thermostat is calling for heat on a cold day
- The “AUX” or “Emergency Heat” indicator on the thermostat displaying but the indoor temperature continuing to fall
- An electric bill that is higher than previous winters without a change in thermostat setpoints — one element open forces the remaining elements to run longer
- A burning smell at the start of the first heating season — dust burning off elements that have been idle since the prior winter
The Airflow Restriction That Causes Premature Element Failure
The most common cause of premature electric strip heater failure in Arlington County air handlers is restricted airflow past the element — typically caused by a dirty air filter, a dirty indoor coil, or a malfunctioning blower motor. The strip heating elements are designed to operate with a specific minimum airflow passing over them to carry heat away and prevent the elements themselves from overheating. When airflow is restricted, the element surface temperature rises above its design operating temperature. Repeated high-temperature cycling accelerates the nichrome wire’s oxidation and embrittlement — advancing the element’s fatigue failure timeline from 15 to 20 years toward 8 to 10 years. The Arlington County homeowner whose strip heater failed at year 9 may have been running a dirty filter for the system’s entire life.
Strip Heater Replacement vs. Heat Pump Upgrade: The Economic Comparison
An Arlington County homeowner facing a failed strip heater replacement has an opportunity to evaluate the alternatives simultaneously. Strip heater replacement in an existing air handler is a moderate-cost repair — typically $300 to $600 for element and sequencer replacement in a single-stage system. For a system that is 15-plus years old with an aging compressor and an aging control board, this repair restores the supplemental heat function while leaving every other age-related risk in place. For the same homeowner, the modern cold-climate heat pump alternative — a variable-speed system with a rated heating capacity at 5°F of outdoor temperature that eliminates the need for strip heaters during most Arlington County winter conditions — makes the strip heater failure a natural trigger for the replacement conversation. PRO Electric plus HVAC presents both options honestly for every Arlington County strip heater failure, letting the homeowner’s specific system age and condition drive the recommendation rather than the size of the invoice.
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Testing Strip Heaters Before Winter: The Fall Maintenance Item Most Technicians Skip
Electric resistance strip heaters in Arlington County heat pump air handlers are typically tested by running the system in emergency heat mode and measuring the temperature rise across the air handler at full element load. This test — which takes 10 minutes and requires a thermometer, an ammeter, and the knowledge of what a correct temperature rise looks like for the installed element wattage — is the definitive way to confirm that every element in the system is energizing and producing its rated output. Most Arlington County maintenance visits do not include this test because it adds time and most technicians do not perform it unless specifically requested. PRO Electric plus HVAC includes strip heater operational testing as part of every fall maintenance visit for systems with electric resistance supplemental heat — specifically because discovering a failed element in October is vastly preferable to discovering it in January.
Serving All of Arlington County — Strip Heater Diagnosis and Replacement
PRO Electric plus HVAC diagnoses and replaces failed electric strip heaters in Arlington County heat pump systems — with fall operational testing, sequencer verification, and honest repair-versus-upgrade recommendations for aging systems where the strip heater failure is not the only age-related issue present.
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Frequently Asked Questions
What are electric strip heaters in a heat pump system?
Electric strip heaters are backup heating elements inside your air handler that activate when outdoor temperatures drop too low for the heat pump to keep up. They function like a built-in electric heater, providing additional heat during the coldest days.
Why is my home not staying warm even though the heat pump is running?
If your home is not maintaining temperature during cold weather, it may be due to a failed strip heater element or a faulty sequencer. When these components fail, the system cannot provide the full amount of supplemental heat needed during low outdoor temperatures.
What are the signs of a failing electric strip heater?
Common signs include weak or lukewarm air from vents, rising energy bills, the thermostat showing auxiliary heat but indoor temperatures still dropping, and breakers tripping during cold weather. These symptoms indicate the system is not delivering its full heating capacity.
Why do electric strip heaters fail earlier than expected?
Premature failure is often caused by restricted airflow. Dirty air filters, clogged coils, or blower issues can cause the heating elements to overheat, accelerating wear and leading to early failure. Proper maintenance helps extend the life of these components.
Should I repair my strip heater or upgrade my heat pump system?
It depends on the age and condition of your system. For newer systems, replacing the strip heater is usually a cost-effective repair. For older systems, upgrading to a modern heat pump that requires less or no supplemental heat may offer better long-term efficiency and lower energy costs.
References
U.S. Department of Energy. (2024). Electric resistance heating. Energy Saver. https://www.energy.gov/energysaver/electric-resistance-heating
Air Conditioning Contractors of America. (2023). ACCA Standard 4: Maintenance of residential HVAC systems. ACCA.
National Fire Protection Association. (2023). NFPA 70: National Electrical Code — Article 424: Fixed electric space-heating equipment. National Fire Protection Association.
American Society of Heating, Refrigerating and Air-Conditioning Engineers. (2022). ASHRAE Handbook — HVAC Systems and Equipment: Electric heating. ASHRAE.
