Heat Pump Repair

Heat pumps suit North Texas well. Most winter days run from the thirties overnight to the fifties by afternoon, the range where a heat pump heats efficiently, and the same unit cools the house all summer. That double duty is also what wears them out. Our winters bring the conditions heat pumps like least: humid mornings near freezing that frost the outdoor coil, and the occasional ice storm that leaves the backup heat doing most of the work.

W3 Electric Heating & A/C repairs heat pumps in Rowlett, Rockwall, McKinney, Garland, Wylie, Forney, and across the wider Dallas area, and we take emergency calls 24 hours a day. A heat pump is as much electrical as mechanical: a defrost board, a reversing valve solenoid, capacitors, a contactor, and backup heat strips that draw more current than almost anything else in your home. Being licensed for both HVAC and electrical work, we can trace a fault from the thermostat to the breaker panel ourselves.

Heat pump repair covers the system that heats and cools your home through one outdoor unit. In winter a heat pump burns nothing. It collects heat from the outdoor air, which still holds usable heat below freezing, and pumps it indoors. A reversing valve switches the direction the refrigerant flows, which is how the same equipment cools in July and heats in January. That design is efficient, and it comes with failures, and false alarms, that a furnace never has.

Our heating repair page covers every type of system that has stopped keeping you warm, from gas furnaces to electric heat. If your heat pump is running fine and you simply want it inspected ahead of the season, you are looking for heat pump maintenance instead.

Plenty of heat pump calls in the first cold week turn out to be a healthy system doing exactly what it was designed to do. These three behaviors are normal, and knowing them can save you a service call.

As the outdoor coil pulls heat from cold, damp air, frost builds on it, and every so often the system clears it on its own. The reversing valve shifts with a loud whoosh, the outdoor fan stops, and warm refrigerant runs through the outdoor coil. You may see steam rising off the unit and water running out underneath, then hear a second whoosh as heating resumes. A defrost cycle usually lasts a few minutes, and your backup heat normally comes on meanwhile so the vents do not blow cold.

A gas furnace delivers air that feels hot, often well over a hundred degrees. A heat pump delivers gentler heat, often only in the nineties at the register, close to the temperature of your skin, so it can feel cool against your hand even while it warms the house. The useful test is not how the air feels but whether the house holds the temperature on the thermostat. Air near room temperature, or plainly cold, while the house loses ground is a different story.

A heat pump loses capacity as the outdoor temperature drops, just as your house starts losing heat faster. On a mild day it cycles on and off like an air conditioner. On a cold night it may run almost without stopping and still be working correctly, and below a certain outdoor temperature it calls on the backup heat, which the thermostat may show as AUX. Long cycles only point to a problem when the house cannot hold temperature, when backup heat runs on mild days, or when the electric bill climbs beyond what the weather explains.

If the defrost control board or the sensor clamped to the outdoor coil fails, frost keeps building until the coil is a solid block of ice and the heat pump can no longer pull heat from the air. The reversing valve fails in its own way: if it sticks, or the solenoid that shifts it fails, the system can blow cool air in heating mode, or heat when you want it to cool. Sometimes the cause is simply a thermostat set up for the wrong reversing valve signal, a common slip after a thermostat replacement.

The refrigerant circuit is sealed, so a low charge almost always means a leak, and a heat pump short on refrigerant heats poorly and ices up quickly. We find the leak and tell you honestly whether it is worth repairing, rather than adding refrigerant that will escape again. Outdoors, the fan motor and the capacitor that starts it wear steadily with year round use, and without that fan the coil cannot collect heat. The contactor that switches the compressor pits and sticks over time. The compressor is the costliest part in the system, so we test it thoroughly before calling it failed.

The electric heat strips in your air handler back up the heat pump, and they fail in two directions. If an element burns out, a sequencer or relay fails, or the breaker feeding the strips trips, the house falls behind on the coldest nights. If a sequencer sticks closed, or the controls call for backup heat when they should not, the strips run far more than they should, the house stays warm, and the problem only shows up on your electric bill. AUX showing on a mild afternoon is one clue, and a thermostat left on EM HEAT is another. These high current circuits are work for a licensed technician.