Diagnostics and repair
When a Heat Pump Stops Keeping Up
Diagnosis first, parts second — because the fix is often airflow or a setting, not a component.
Most heat pump faults show up as one of three symptoms: no heat, short-cycling, or a system leaning on backup electric heat. Ladysmith Heat Pumps diagnoses before ordering parts across Ladysmith, Chemainus and Saltair, where salt corrosion on outdoor coils drives a large share of early failures. Repair gets compared against a $3,500 to $18,000 replacement before rebates.
A heat pump that has stopped performing is usually not broken in the way people assume. Before a compressor gets condemned, there are cheaper explanations worth ruling out.
Diagnostic visits are quoted per call, and repairs vary widely with the component — a control board or sensor sits at the low end, a compressor or coil replacement at the high end where replacing the system often becomes the better value. On an aging unit the comparison worth running is repair cost against a new install at $3,500 to $18,000 before the CleanBC rebate. Ranges only; a diagnosis comes first.
The three symptoms, and what they usually mean
No heat at all is most often electrical or control-side rather than mechanical — a tripped breaker, a failed contactor or capacitor, or a thermostat switched to a mode nobody intended. Compressor failure does happen, but sits far down the list of first checks.
Short-cycling, where the system starts and stops every few minutes, points at oversizing, low refrigerant charge, or restricted airflow. On systems installed without a heat loss calculation, oversizing is the common cause — and no repair fixes that, because the system is doing what an oversized unit does.
Running on backup heat is the expensive symptom, because households usually notice a hydro bill rather than a fault. A heat pump that has quietly stopped carrying the load hands off to resistance elements and keeps the house warm while consuming several times the electricity. That can continue for a full winter unnoticed.
What salt air does over time
The failures that arrive early on this coast are corrosion failures. Salt carried off Ladysmith Harbour and the Saltair shoreline settles on outdoor coils, cabinet fasteners and service valves, and works on them continuously rather than seasonally.
Corroded coil fins lose heat transfer before they look damaged, so the system compensates by running longer and eventually hands off to backup heat — which is why a corrosion problem often presents as a performance complaint rather than a visible one. Fasteners seize, panels become difficult to open without damage, and valve stems weep.
Rinsing the outdoor coil with fresh water several times a year is the single most effective maintenance action available to a homeowner here, and costs nothing. Units without coastal protection benefit most, because they have the least margin.
Repair or replace
The honest answer depends on age, on which component failed, and on what the rebate does to the replacement side of the comparison.
Control boards, capacitors, contactors, sensors and fan motors are generally worth repairing at almost any system age. Compressors and outdoor coils are not, on an older unit — the part cost approaches a meaningful fraction of a new system, and the rest of the equipment is the same age as the part that just failed.
What changes the arithmetic here is the rebate. A replacement that qualifies under the CleanBC Energy Savings Program can be substantially cheaper than the sticker suggests, and a household weighing a large repair against replacement should have both numbers, with the rebate applied, before deciding.
How a service call runs
- 1
Symptom, then history — What the system is doing, when it started, and what changed around it. A unit that stopped after a power event points somewhere different from one that has degraded over two winters.
- 2
Airflow and settings first — Blocked filters, a dirty outdoor coil, a thermostat set to emergency heat, and closed supply registers account for a large share of no-heat calls. All are checked before anything is opened up.
- 3
Electrical and refrigerant — Voltage at the unit, contactor and capacitor condition, defrost operation, and refrigerant charge. Low charge means a leak, and a leak means finding it rather than topping up and rebooking.
- 4
Repair or replace, stated plainly — For an older system the repair cost gets put next to a replacement quote with the rebate applied, so the decision is made on numbers rather than pressure.
What the job includes
Heat pump diagnostics
Symptom-led diagnosis covering airflow, controls, electrical and refrigerant charge before any part is ordered.
Component repair and coil replacement
Repair of control boards, capacitors, contactors, fan motors and corroded outdoor coils, with a replacement comparison where age warrants one.
Where systems fail first
Systems within sight of the water show corrosion earliest. Inland installs toward Yellow Point tend to fail on more conventional causes — airflow, controls, and age.
In practice
- Situation
- An eight-year-old ductless system in Saltair, still heating, but with a hydro bill that had climbed steadily over two winters.
- Complication
- Nothing presented as a fault — the system ran and the house was warm, so no service call had been made.
- Resolution
- The outdoor coil had corroded enough to lose capacity, and the backup elements had been covering the shortfall. Coil replacement restored output and the bill returned to its previous level.
People also ask
How do you know if a heat pump is running on backup heat?
The clearest signal is a hydro bill rising with no change in habits. Many thermostats display an auxiliary or emergency heat indicator when the elements engage. A system that runs constantly without the outdoor unit sounding is another sign.
Is a refrigerant top-up a real repair?
No. A sealed system does not consume refrigerant, so low charge means a leak. Topping up without finding the leak returns the system to the same condition within a season and vents refrigerant in the meantime.
How long should a heat pump last?
Fifteen to twenty years is typical, and less on a salt-exposed site without coastal protection or regular coil rinsing. Units that reach the upper end are generally the ones that were correctly sized, so they were not cycling hard for their whole life.
Can a heat pump be repaired in winter?
Yes, and that is when most calls happen. The constraint is parts availability rather than weather — a common control component is usually same-week, while a compressor or coil for an older model can take longer to source.
Three pages worth reading before booking a repair: what a replacement would involve, or compare that against how repair compares against replacing. Ladysmith Heat Pumps also covers why coastal systems age faster.
Start with the house
Address, current heating system and rough timing are enough for a first conversation.