How do I know if I have a heat pump or a regular AC?

Check your thermostat — if it has an "Emergency Heat" or "Aux Heat" setting, you likely have a heat pump. You can also look at the outdoor unit's label for the model number. Heat pump models typically start with a prefix like "HP" or include "heat pump" on the data plate. If you are not sure, call Action Mechanical Services at 480-450-7283 and describe the equipment — we can usually identify it over the phone.

Why is my heat pump blowing cold air in heating mode?

The most common causes are a failed reversing valve (stuck in cooling mode), low refrigerant charge, a defrost cycle in progress (temporary cold air is normal during defrost), or a thermostat wired or configured incorrectly. If the outdoor unit is not running at all, the problem may be a failed contactor, capacitor, or compressor.

How much does heat pump repair cost in Tempe?

Heat pump repairs in Tempe typically range from $175 to $800 depending on the problem. Capacitor and contactor replacements are on the lower end. Reversing valve replacement, refrigerant leak repair, and compressor replacement are more involved and cost more. Action Mechanical Services provides upfront quotes before beginning any repair work.

Can a heat pump work in Tempe's winter temperatures?

Yes. Tempe's winter lows averaging around 44 degrees are well within the efficient operating range for modern heat pumps. Heat pumps lose significant efficiency only when outdoor temperatures drop below 25-30 degrees, which is rare in the Phoenix metro area. Heat pumps are an excellent heating choice for Tempe homes.

How long do heat pumps last in Arizona?

Heat pumps in the Phoenix area typically last 12 to 16 years. The extended operating season (cooling and heating) means more total runtime than in milder climates, which can shorten lifespan compared to national averages. Regular maintenance extends heat pump life significantly. When repair costs on an aging heat pump become frequent, Action Mechanical Services can discuss replacement options.

Heat Pump Repair Tempe, AZ | Action Mechanical

Heat pumps are the year-round workhorses of Arizona home comfort, providing both air conditioning in the summer and heating in the winter from a single system. When your heat pump fails — whether it stops cooling during a 107-degree July afternoon or refuses to heat on a 44-degree January night — Action Mechanical Services provides expert heat pump repair to get it running again fast.

Action Mechanical Services technician servicing an AC unit

Unlike a standard air conditioner that only cools or a furnace that only heats, a heat pump moves thermal energy in both directions. This dual-mode operation means a heat pump has additional components that a standard AC does not — most notably the reversing valve and defrost controls — and repairing one correctly requires a technician who understands both sides of the system.

How Heat Pumps Work in the Phoenix Climate

In cooling mode, a heat pump operates identically to a conventional air conditioner: the outdoor unit compresses refrigerant, the condenser coil releases heat outdoors, and the evaporator coil inside the air handler absorbs heat from your indoor air. In heating mode, the reversing valve switches the refrigerant flow direction, causing the outdoor coil to absorb heat from the ambient air and the indoor coil to release it into your home.

The Phoenix metro area is ideal territory for heat pump heating because winter temperatures in Tempe rarely drop below 44 degrees. Heat pumps lose efficiency as outdoor temperatures approach freezing, but Tempe’s mild winters keep the system operating well within its efficient range for the vast majority of the heating season. This is why heat pumps have become the default heating solution in newer Arizona construction.

Common Heat Pump Failures We Repair

Many homes in the area were built over 30 years ago, meaning original HVAC equipment is well past its expected lifespan. Our technicians see these heat pump problems regularly in Tempe service calls:

Reversing valve failure — The reversing valve switches the system between heating and cooling mode. When it fails or the solenoid coil burns out, the heat pump may get stuck in one mode. Some reversing valves fail partially, allowing refrigerant to bypass internally and reducing heating or cooling capacity without stopping the system entirely.
Compressor issues — The compressor is the heart of the heat pump. Hard starts, unusual noises, tripped breakers, or a unit that runs but provides weak heating or cooling all point to compressor problems. Failed run capacitors, locked rotors, and internal valve leaks are the most common compressor-related failures.
Refrigerant leaks — Heat pumps in Tempe run extensively during both summer and winter, putting more total operating hours on refrigerant connections than a cooling-only system. Slow leaks at service valves, flare fittings, or the coil itself reduce system capacity gradually. Low refrigerant in heating mode produces lukewarm air and can damage the compressor.
Defrost board and sensor failures — During heating mode, moisture from the outdoor air can form frost on the outdoor coil. The defrost control board monitors coil temperature and initiates defrost cycles to melt accumulated ice. A failed defrost board or temperature sensor allows ice to build up until airflow is blocked and the system shuts down on safety limits.
Outdoor fan motor failure — The outdoor fan motor runs during both heating and cooling. In Arizona, these motors endure extreme summer heat and accumulate fine desert dust in their bearings. A seized or sluggish fan motor causes the outdoor coil to overheat in cooling mode or ice over in heating mode.
Contactor and capacitor failures — Contactors engage the compressor and fan motor circuits. Capacitors provide the electrical boost needed to start and run these motors. Arizona heat accelerates capacitor degradation — a failed capacitor is the single most common heat pump repair in the Phoenix area.

Is your heat pump not performing properly? Call 480-450-7283 for expert heat pump diagnostics in Tempe.