Heat pump installation: what to expect and how to pick an installer

1. Home assessment and sizing. The contractor measures the house and runs a load calculation. ENERGY STAR advises that sizing be verified with a Manual J calculation, since a system that is too large or too small struggles to keep you comfortable.
2. Duct and electrical check. The ducts are inspected for leaks and size. The panel is checked for capacity, especially if electric backup heat is being added.
3. Removal. Old refrigerant is recovered and the old equipment is taken out.
4. Setting the equipment. The outdoor unit goes on a pad or stand, raised above expected snow where winters call for it. The air handler or coil goes in indoors.
5. Refrigerant lines. Lines are run or replaced, brazed, pressure tested and pulled into a deep vacuum to remove air and moisture.
6. Wiring and controls. Power, the disconnect, the thermostat and backup heat staging are connected and configured.
7. Charging and startup. Refrigerant charge is set by measurement. Airflow, heating, cooling, defrost and backup heat are all tested.
8. Walkthrough. You get the thermostat explained, the filter location shown and the warranty paperwork.

A straight replacement that reuses sound ducts and wiring is the quickest job. Time goes up when the contractor has to replace refrigerant lines, repair or add ducts, run a new electrical circuit, upgrade the panel, or work in an attic or crawlspace. Ductless systems with several indoor units and geothermal systems with ground loops take longer. Ask each installer for a schedule in writing, including the inspection.

• Clear a path to the indoor unit, the electrical panel and the outdoor unit.
• Move cars, furniture and stored items out of the work areas.
• Keep pets and children away from the work.
• Decide where you want the thermostat if it is being moved.
• Have the signed quote on hand so you can check that the model numbers delivered match it.
• Plan for no heating or cooling during the work.

The quality of the installation affects comfort, running cost and equipment life as much as the equipment brand does. Look for these signs:

• A state or local contractor license and proof of insurance, which you can verify with your state licensing board.
• A load calculation done for your house, with the result shown to you.
• A permit pulled in the contractor's name.
• An itemized written quote with model numbers, ratings, scope of work and warranties.
• Regular heat pump work, including cold-climate models and backup heat setup if your region needs them.

Be wary of a bid that sizes the system from square footage alone, skips the permit, or pushes you to sign that day. For what the price should cover, see the page on heat pump cost.

• What size did the load calculation call for, and may I see it?
• Are you reusing or replacing the refrigerant lines, and why?
• What duct repairs are included?
• What backup heat will the system have, and at what outdoor temperature will it take over?
• What do the parts warranty and your labor warranty cover, and who registers the equipment?
• What tests will you run at startup, and will I get the results?

The heat pump overview explains the system types if you are still choosing between ducted, ductless and dual fuel.