My heat pump cools but will not heat. Is the compressor dead?

Usually not. That symptom points at the reversing valve or its solenoid, and a low charge can mimic the same fault. We meter the solenoid and check valve operation before condemning anything, because a unit written off as a bad compressor is often a $300 reversing valve or a $40 sensor.

Is it normal for my heat pump to ice over in winter?

Light frost is normal and the defrost cycle should clear it. A unit iced solid has a failed defrost board, sensor, or reversing valve and is losing heating capacity. We test the full defrost cycle on a service call instead of telling you to pour warm water on it.

Do you work on inverter and variable-speed heat pumps?

Yes. Daikin, Mitsubishi, and modern Goodman inverter systems report specific faults: IPM overcurrent, sensor drift, communication loss between boards. We read the code, follow the manufacturer flowchart, and replace the component that actually failed. These are the systems where guessing gets expensive fast.

Why is my electric bill huge but the house barely warm?

The backup heat strips are carrying the load because the heat pump is not keeping up. That shows on the PG&E bill before it shows as no heat. Often the cause is a low charge from a slow leak; we find it, repair it, and weigh the system back to spec.

What does a heat pump diagnostic cost?

The diagnostic is $75, waived when you book the repair, and $50 for returning customers. We are EPA Section 608 Universal certified, diagnose with superheat and subcooling, and read inverter fault codes against the manufacturer service data. You get the quote in writing before any work starts.

HVAC service · Bay Area

Heat Pump Repair · Bay Area

Reversing valves, defrost boards, inverter and variable-speed faults, low charge. Cooling and heating from one system, diagnosed correctly.

By Andrew Kuznetsov, Owner and Lead Technician, CSLB #1136642 Updated June 30, 2026

$75 diagnostic (waived with repair)
Same or next-day best effort
Insured · CSLB #1136642

Call (925) 999-4095

Old and new outdoor main control boards side by side during a Samsung mini-split heat pump repair in Pleasanton — Main-board replacement on a Samsung mini-split in Pleasanton. Inverter heat pumps are board-level work.

What we do. What we fix.

What we do

ADRIUM repairs heat pumps across 39 East Bay and Tri-Valley cities: reversing valves, defrost boards, inverter and variable-speed faults, and low-charge diagnosis, EPA 608 certified, with a $75 diagnostic waived with repair. Heat pumps are the system the Bay Area is moving to, and they are the system most general HVAC techs diagnose poorly. A heat pump is an air conditioner that runs in both directions, so it has everything an AC has plus a reversing valve, a defrost board, and on modern units an inverter-driven compressor, and each of those adds a failure mode that needs a tech who understands the refrigerant cycle, not a parts-swapper.

We are EPA Section 608 Universal certified and carry a digital manifold, recovery machine, and charging scale. We diagnose with superheat and subcooling, we recover and weigh in refrigerant by the nameplate, and we read inverter fault codes against the manufacturer service data instead of guessing.

A Heat Pump We Installed and Service

Goodman heat pump condenser installed against a home exterior with disconnect box and refrigerant lineset in Union City — A Goodman heat pump condenser on a Union City install. Neat lineset, proper disconnect, level pad. The same care that goes into an install is what makes a future repair fast, because we can get at the service ports and the wiring without fighting the work someone rushed.

Common issues. Typical repair.

Cools fine, will not heat (or the reverse). This points straight at the reversing valve or its solenoid. A stuck valve or a failed solenoid coil traps the system in one mode. We meter the solenoid and check the valve operation before condemning the part, because a low charge can mimic the same symptom.

Outdoor unit ices over in winter. A heat pump is supposed to frost and then defrost. When the defrost board, sensor, or reversing valve fails, the unit ices solid and loses heating capacity. We test the defrost cycle on a service call rather than telling you to pour warm water on it.

Inverter unit throws a fault code and shuts down. Daikin, Mitsubishi, and modern Goodman inverter systems report specific faults: IPM overcurrent, sensor drift, communication loss between indoor and outdoor boards. We read the code, follow the manufacturer flowchart, and replace the actual failed component. These are the systems where guessing gets expensive fast.

Weak heat on cold mornings. Often a low charge from a slow leak, sometimes a failing compressor. We measure rather than assume, find and repair the leak, and weigh the system back to spec.

Auxiliary or backup heat running constantly. The electric heat strips or backup are carrying the load because the heat pump is not. That shows up as a high PG&E bill before it shows up as no heat. We find why the compressor side is not keeping up.

Why the right tech matters on a heat pump

A heat pump diagnosed as “the compressor is bad” is often a $300 reversing valve or a $40 sensor. The reverse is also true: a tech who keeps adding refrigerant to a leaking inverter system burns through your money and the compressor. We diagnose to the failure, give you the repair-versus-replace numbers honestly on older units, and stand behind the work.

Our HVAC division

Heat pumps are the focus of our sister brand, Bay Area HVAC Service, including Title 24 and Manual J work on replacements. Same owner, same trucks, same credentials.

Heat Pump brands, by tier.

Cities we cover across the Bay Area.

Don't see your city? We cover most of the Tri-Valley, Diablo Valley, Inner East Bay, and Mid-Peninsula. Ask when you call.

Pricing & warranty

No mystery numbers.

Diagnostic

$75

Waived when you book the repair with us.
Repair warranty

3 mo to 1 yr

Parts + labor on completed repairs. Term varies by part.
Repair cost

Quoted

Final cost depends on parts and the time the job takes. Written quote before we start.

What do customers ask about Heat Pump Repair?

My heat pump cools but will not heat. Is the compressor dead?

Usually not. That symptom points at the reversing valve or its solenoid, and a low charge can mimic the same fault. We meter the solenoid and check valve operation before condemning anything, because a unit written off as a bad compressor is often a $300 reversing valve or a $40 sensor.
Is it normal for my heat pump to ice over in winter?

Light frost is normal and the defrost cycle should clear it. A unit iced solid has a failed defrost board, sensor, or reversing valve and is losing heating capacity. We test the full defrost cycle on a service call instead of telling you to pour warm water on it.
Do you work on inverter and variable-speed heat pumps?

Yes. Daikin, Mitsubishi, and modern Goodman inverter systems report specific faults: IPM overcurrent, sensor drift, communication loss between boards. We read the code, follow the manufacturer flowchart, and replace the component that actually failed. These are the systems where guessing gets expensive fast.
Why is my electric bill huge but the house barely warm?

The backup heat strips are carrying the load because the heat pump is not keeping up. That shows on the PG&E bill before it shows as no heat. Often the cause is a low charge from a slow leak; we find it, repair it, and weigh the system back to spec.
What does a heat pump diagnostic cost?

The diagnostic is $75, waived when you book the repair, and $50 for returning customers. We are EPA Section 608 Universal certified, diagnose with superheat and subcooling, and read inverter fault codes against the manufacturer service data. You get the quote in writing before any work starts.

Tell us what's broken. We'll quote it.