Heat Pump Repair Brooklyn

Every heat pump ices its outdoor coil in cold, damp weather and runs a defrost cycle to clear it — a few minutes of steam off the outdoor unit and cool air indoors, then back to heat. That is normal. A unit that defrosts every few minutes, stays in defrost for a long stretch, or comes out of it still caked in ice is not: the defrost board, the coil sensor, the outdoor fan, or a low charge is usually behind it. Ice that never clears also chokes airflow across the outdoor coil, so heating capacity collapses on exactly the days you need it. We watch a full defrost run rather than guess from a description.

Cool air in heat mode can be a reversing valve that never shifted, a thermistor feeding the board a wrong temperature so it never calls for heat properly, or a charge that has drifted low enough that the outdoor coil can't pull heat from the air. On inverter systems a bad sensor also shows up as erratic compressor speed and short cycles. We test each in order — valve solenoid and line temperatures, sensor resistance against the chart, then pressures with superheat and subcooling — instead of swapping the most expensive part first.

Cold-climate models keep most of their capacity into the single digits, but a system that was sized for cooling, or one running a dirty filter or a low charge, loses ground fast below freezing. If the house has electric backup heat, we check that it engages when it should; if it never engages, or runs all the time, that is a control or sensor problem, not the weather. If your backup is a gas furnace — a dual-fuel setup — the furnace has its own failure points; see Furnace Repair Brooklyn. And if a heat pump alone has never kept the house warm on the coldest nights, adding or replacing a gas furnace as backup is a fair conversation — furnace installation and replacement explains sizing and what a quote includes.

Modern cold-climate systems (Mitsubishi H2i, Fujitsu Halcyon, Daikin AURORA) are rated to -13°F. If your system is icing up or losing heating capacity in cold weather, the likely causes are restricted airflow — a dirty indoor filter can restrict indoor airflow, while a dirty or obstructed outdoor coil can restrict airflow through the outdoor unit — a refrigerant charge that's drifted low, or a defrost board that's not triggering properly. These are fixable — not a reason to replace the system.

The same unit cools in July, and summer failures look like any air conditioner's — warm air, water at the indoor head, a tripped breaker, an outdoor unit that won't start. The diagnosis is the same discipline: airflow first, electrical second, refrigerant last. Cooling-mode repair stays on this page year-round.