A heat pump is an air conditioner that can run in reverse to heat, which means it has everything an AC has plus a reversing valve and a defrost cycle — two more things that can fail. Lennox heat pumps are efficient and well-built, but the high annual hours in SoCal mean the wear parts come due on schedule. This page is the Lennox-specific companion to our general heat pump repair service and our Lennox brand overview. Common failure modes have dedicated guides: not heating, not cooling, not defrosting, reversing valve, and won’t turn on.
Common Lennox heat pump failures
- Run-capacitor and contactor wear on EL18XPV and single-stage heat pumps from the high annual run-hours. Same predictable pattern as any outdoor unit. Capacitor $185–$295, contactor $165–$285.
- Reversing-valve / solenoid faults — the system gets stuck in heating or cooling and will not switch. A heat-pump-specific repair.
- Defrost-control faults — the outdoor coil ices over in heating mode because the defrost cycle is not running, or the system never exits defrost.
- Low-pressure trips (E227) — a slow refrigerant leak at a service valve or the coil. Detection $245–$485.
- iComfort communication faults (E200/E201) on the C-wire bus — the iComfort S30 logs the code with a timestamp.
- Condenser fan motor wear, often a grinding bearing before it quits. $485–$795.
Stuck in one mode, or icing up
The two failures that feel uniquely “heat pump” are a system stuck in one mode and an outdoor unit that ices over. A heat pump that cools fine but will not heat (or vice versa) usually has a reversing-valve solenoid that stuck or failed — the valve flips refrigerant flow between modes, and when it sticks the system runs only one way. Heavy, persistent ice on the outdoor coil in heating mode points at a defrost-control fault, a low charge, or a failed outdoor fan; a little frost that clears on its own is the normal defrost cycle doing its job. We meter the valve solenoid and the defrost board before quoting. Reversing-valve and defrost-system pricing is on our heat pump repair page; the no-start chain is in our AC not turning on guide and the noise diagnosis in HVAC strange noises.
Why Lennox heat pumps fail when they do in SoCal
Heat pumps run both seasons here — 1,500–2,500 hours a year inland in Pasadena, Burbank, the Inland Empire, and the Conejo Valley, where heat-cycling cooks capacitors and contactors at year 8–12. On the coast in Santa Monica, Manhattan Beach, and Malibu, salt air corrodes the outdoor electricals at year 5–8. In the high desert and mountains (Big Bear, Wrightwood) the heating hours are real and the defrost cycle works hard, so defrost and reversing-valve faults show up more there than in the warm valleys. The frozen-coil mechanics carry over from cooling season too — see frozen evaporator coil.
Lennox heat pump repair pricing
Flat-rate on the shared components, parts and labor, from our SoCal service tickets. Heat-pump-specific parts (reversing valve, defrost control) are quoted on our heat pump repair page. Diagnostic is $89 ($149 after-hours), credited to the repair:
| Lennox heat pump repair | Typical cost |
|---|---|
| Diagnostic (waived with repair) | $89 / $149 after-hours |
| Dual-run capacitor | $185–$295 |
| Single-run capacitor | $145–$245 |
| Contactor | $165–$285 |
| Condenser fan motor | $485–$795 |
| TXV | $585–$895 |
| Compressor (out of warranty — we quote replacement) | $2,400–$4,200 |
Lennox’s standard warranty carries 10 years on the compressor when registered within 60 days; labor is separate. We confirm coverage before ordering.
Repair or replace your Lennox heat pump
Under 8–10 years with a capacitor, contactor, or defrost-board fault, repair it. Over 12–15 years with a compressor or reversing-valve failure, replacement usually wins — especially on a pre-2010 R-22 unit. Because heat pumps run more hours than a cooling-only AC, they reach the replace threshold a bit sooner. We model the repair against a written replacement quote, and we walk the heat-pump-versus-AC tradeoffs honestly in our heat pump vs. air conditioner guide. See heat pump installation when replacement is the call.
iComfort diagnostics on heat pumps
A communicating Lennox heat pump reports through the iComfort S30 with the same alert-code family as the rest of the system — we read the timestamped fault history on arrival. The full code reference is on our Lennox error codes page. For the cooling-only side, see Lennox AC repair and Lennox AC not cooling, and the full lineup on our Lennox brand page.