Heat Pump Repair in Austin, TX

Heat Pumps in Austin Homes

A heat pump looks like an air conditioner and cools like one in summer. In winter a reversing valve flips the flow so the outdoor unit pulls heat from outside air and moves it indoors. Heat pumps are common across Austin, especially in newer homes, condos and apartments, and in newer neighborhoods like Mueller where electric heat is the norm.

Because a heat pump runs in both seasons, it works far more hours each year than a furnace does. The compressor, the outdoor fan motor and the capacitors carry that load year round.

Heat Pump Repair Work in Austin

• Reversing valves and their solenoid coils
• Defrost boards and the coil sensors that trigger defrost
• Outdoor fan motors, contactors and capacitors
• Backup heat strips, sequencers and relays
• Thermostats set up for heat pumps, including emergency heat settings
• Indoor blower motors and air handler controls

Signs that point to a repair: the system blows cool air in heat mode, the outdoor unit is covered in ice that does not clear, the emergency heat light stays on, or the system heats but will not cool in spring. Call (737) 295-1994.

Defrost and Backup Heat

On cold mornings, frost can build on the outdoor coil. The defrost board senses it and briefly switches the system to cooling mode to melt the frost, and a cloud of steam from the outdoor unit during defrost is normal. If defrost fails, the coil ices solid and heat output drops. The backup heat strips then carry the house, which works but runs up the electric bill.

A heat pump that runs on backup heat all the time, short cycles, or makes a loud grinding or buzzing noise from the outdoor unit has a fault somewhere. So does one that leaves the house cooler than the set point while the outdoor fan never stops.

Heat Pump Repair Questions

Why does my heat pump have two capacitors?

Many heat pumps use one capacitor for the compressor and outdoor fan, often a dual capacitor in one can, and a separate one for the indoor blower motor. Some also add a start capacitor to help the compressor start under load. Each one can fail on its own, which is why a heat pump can have a running fan and a silent compressor, or the other way around.

Why is my emergency heat coming on?

Backup heat comes on when the heat pump cannot keep up, during defrost, or when the thermostat is calling for a large jump in temperature. On a cold morning that is normal for short stretches. If the emergency heat light stays on all the time, the heat pump may have locked out, the outdoor unit may be iced over, or the thermostat may be set or wired wrong.

Can a heat pump give off a smell?

Yes, and the smell says a lot. A dusty or burning smell the first time the backup heat strips come on for the season is common and should fade quickly. A musty smell usually points to standing water in the drain pan or a dirty indoor coil. A sharp electrical or burning plastic smell can mean a failing motor, a scorched wire or an overheating control board, and the system should be shut off until it is checked.

Does a heat pump need a furnace?

No. Most heat pumps in Austin pair with an indoor air handler that has electric heat strips for backup. Some homes use a dual fuel setup, where a gas furnace replaces the heat strips as backup and takes over on the coldest nights. Either works. The thermostat has to be set up to match the equipment so the backup heat comes on at the right time.

Can a dirty filter cause heat pump to freeze?

Yes, in summer. A dirty filter cuts airflow across the indoor coil, and in cooling mode that coil can drop below freezing and ice up. In winter, the outdoor coil can ice up when defrost fails or when the outdoor unit is blocked by leaves or shrubs. A clean filter and a clear space around the outdoor unit prevent both.

How do I know if my HVAC system has a heat pump?

Check the outdoor unit label: heat pump models usually say so. Another test is to set the thermostat to heat on a mild day and feel the outdoor unit. If its fan runs and it blows cool air out the top, it is a heat pump. A thermostat with an emergency heat setting is another strong sign.

Heat Pump Repair Resources

• AHRI heating and cooling manufacturers
• ASHRAE heating and cooling engineers
• Mueller Community on Wikipedia