Tell us about the job
Takes about a minute. No obligation.
A heat pump asked to carry a long heating load builds wear on specific parts: the compressor cycling through cold mornings, the reversing valve switching modes, the coil working through frost conditions that drop outdoor capacity. Homes in Sonoma County, CA run heat about seven months a year, from November through May. Contractors diagnosing a failed heat pump here routinely find the refrigerant circuit and the reversing valve at the center of the problem, because those are the components the heating season actually stresses. Backup heat sizing comes into the picture too, since a heat pump losing capacity in January asks a lot of any supplemental strip heat installed behind it.
Half the homes in Sonoma County, California were built in 1979 or earlier (2020-2024 ACS 5-year). A house that has lived through that many equipment generations has often had its heat pump retrofitted into ductwork and wiring that predates it, which means what a contractor finds once the unit is open can diverge sharply from what the permit history or the visible components suggest. Refrigerant fittings, control boards, reversing valves: if the system is old enough that the part is discontinued, the repair conversation changes into a sourcing conversation first. That is what decides how the job goes in much of this county.
The Parts of a Heat Pump a Contractor Checks First
The outdoor unit is the piece most homeowners recognize on sight. It sits outside on a pad or bracket and holds the compressor, which does the hardest mechanical work in the system, along with the outdoor coil and a fan that pulls air across it. When a heat pump stops heating or cooling, the compressor and outdoor coil are where a contractor looks first.
Inside the house, the air handler hangs in a closet, attic, or utility room and contains the indoor coil, a blower fan, and the filter housing. A refrigerant line set runs between the two units, and an expansion valve meters the refrigerant as it moves. The thermostat on the wall ties the whole system together and is often the first thing a contractor checks before opening anything up.
The drawing shows the general layout of a heat pump system, and a licensed contractor determines which components and conditions apply to your specific home.
Get matched in Sonoma CountySonoma County, by the numbers
142 severe weather events were recorded in Sonoma County, California between 2015 and 2024.
NOAA National Centers for Environmental Information, Storm Events Database, bulk CSV export, events 2015-01-01 through 2024-12-31.Half the homes in Sonoma County, California were built in 1979 or earlier (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesSonoma County, California holds 207,699 housing units (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesOwners occupy 62.6% of the occupied homes in Sonoma County, California (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesCodes & Standards Covering Heat Pump Repair in Sonoma County, California1 sourced rules & standards
Licensing and Legal Requirements in Sonoma County, California
California requires a state contractor license: it is a misdemeanour to engage in the business of, or act in the capacity of, a contractor in California without one, unless the work is exempt.
Weather Events in Sonoma County That Stress HVAC Equipment
Heat pumps work harder when outdoor conditions are extreme, and that added strain is where wear turns into repair. How often that pressure shows up in Sonoma County is a local variable, and it shapes what contractors here deal with year after year.
142 severe weather events, 2015–2024. Source: NOAA National Centers for Environmental Information, Storm Events Database.