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Commercial · Commercial Heat Pump Service & RepairCommercial Heat Pump Service & Repair
Commercial heat pump service and repair covers three classes of equipment: rooftop heat pumps, including dual-fuel units with gas backup; split heat pumps in the 6 to 20 ton range; and water-source heat pumps tied to a building loop. Five faults cover the calls we plan for: a stuck reversing valve, a failed defrost board or sensor, a compressor problem, lost loop flow or loop temperature on water-source units, and a plugged condensate drain. A unit that cools while calling for heat, ices solid outdoors or trips on high pressure should be switched off and diagnosed, not reset.
The three classes fail differently because they collect and reject heat differently. A rooftop heat pump and a split heat pump both use an outdoor coil, so they frost in winter and depend on a defrost cycle. A water-source heat pump has no outdoor coil at all: it sits above a ceiling or in a closet and exchanges heat with a water loop that a boiler and a cooling tower or fluid cooler hold in a working range, typically about 16 to 32°C. A dual-fuel rooftop unit is a heat pump with a gas heat section, and its controls decide which of the two runs.
On air-source units the reversing valve and the defrost system are the parts a plain air conditioner does not have. A reversing valve that sticks part-way leaves the unit neither heating nor cooling properly, and a failed solenoid coil leaves it stuck in one mode; we confirm by reading temperatures across the valve ports before condemning it, because replacing one means recovering the charge and brazing. A defrost fault shows as an outdoor coil cased in ice, or as a unit that defrosts constantly and never catches up, and the cause is usually a coil sensor, an outdoor sensor or the defrost board. Smaller-scale versions of those repairs are described under reversing valve replacement and defrost board replacement.
Water-source units fail on the water side first. With too little loop flow, a unit trips on high pressure in cooling and on its low-temperature safety in heating; the usual reasons are a plugged strainer, a closed or failed valve, a kinked hose kit or a circulating pump that is down. If every unit in the building trips on the same day, the loop itself is out of range, meaning the boiler or the heat-rejection equipment is off, and resetting individual units will not help. A plugged condensate drain is the other frequent call, and because these units sit above ceilings it announces itself as a stained tile.
Dual-fuel rooftop units save money only if the switchover temperature is set on purpose. That setting is the outdoor temperature at which the controls stop the compressor and bring on gas, and it should come from the unit's heating capacity in cold weather and from what the building pays for electricity and gas. Left at a cautious default, the unit burns gas through most of the winter and the heat pump never earns its keep; set too low, the space falls behind on cold mornings. A quick check: if the unit is firing gas at +5°C outdoors with no fault showing, the switchover deserves a second look.
Incentives for a business are commercial, not residential. The Home Renovation Savings Program is for homes; the route for commercial and institutional buildings is the IESO's Save on Energy Retrofit program, which is open to owners and lessees and requires a pre-project application and approval before the work goes ahead. Whether a particular heat pump qualifies, and for how much, depends on the program's current measure list, so no figure appears here. Our commercial HVAC rebates page follows the program.
Opening the refrigerant circuit on commercial equipment is restricted work in Ontario, done by a 313A refrigeration and air conditioning systems mechanic who holds an ODP card. Repair cost depends on tonnage, refrigerant type and quantity, crane or roof access and parts lead time, so we quote in writing after diagnosis and publish no flat commercial figure. House-sized systems are covered on the heat pump repair page and the overview is at commercial HVAC. To book a diagnosis, contact the shop with the model number and any fault code in hand.
Equipment we install and service
Packaged units that heat and cool from the roof. The dual-fuel version adds a gas heat section, which makes it a gas appliance under TSSA rules as well as a refrigeration system, and gives it a switchover setting worth checking every fall.
An outdoor heat pump unit piped to an indoor air handler, often with two compressors or two refrigerant circuits so one can carry part load. Long line sets make charge and oil return more sensitive, and electric or hydronic backup heat in the air handler needs its own test.
Self-contained units, one per zone, each with a compressor, a water coil and a condensate pan, connected to the building loop by hoses and valves. They are common in office buildings and condos, and their health depends as much on loop flow, loop temperature and water quality as on anything inside the cabinet.
Defrost boards and sensors, pressure switches, low-temperature cut-outs on water coils and the thermostat's heat pump configuration. A thermostat set up for a conventional unit can run a heat pump in the wrong mode or leave its backup heat on full time.
What goes wrong in these buildings
- The unit blows cold air in heating mode and the thermostat insists it is heating.
- The outdoor coil is a solid block of ice and has been for two days.
- Half the heat pumps on the third floor tripped the same morning and maintenance keeps resetting them.
- We bought a dual-fuel rooftop unit to cut gas and the gas bill did not move.
- There is a brown stain spreading on the ceiling tile under the unit in the corridor.
- Our contractor quoted the homeowner rebate and then found out a business cannot claim it.
How it works
We record the unit type, tonnage, refrigerant and control set-up, pull stored fault codes and check the thermostat configuration. On water-source units we take loop supply and return temperatures and the pressure drop across the unit first, since most water-side faults are found before a gauge goes on the refrigerant circuit.
The unit is run in heating and cooling, the reversing valve is switched and checked by temperature, a defrost is forced and timed, and compressor current, pressures and line temperatures are compared with the manufacturer's data. You get the finding and a written price before any refrigerant is recovered.
After the repair, defrost settings, backup heat staging and the dual-fuel switchover are set deliberately and written on the service report. Drain pans and traps are cleaned, strainers are flushed on water-source units, and the report lists the readings so next year's technician has a baseline.
Common questions
Can a commercial heat pump heat a building through an Ontario winter?
It depends on the equipment. A standard rooftop heat pump loses capacity as the temperature falls and relies on backup heat, electric or gas, on the coldest days. Cold-climate models hold more of their capacity, and water-source units are unaffected by outdoor temperature because they draw from the loop. The question to ask of any quote is what carries the building at −20°C and what that costs to run.
Why is the heat pump blowing cold air during heating?
Three causes cover most cases. A normal defrost cycle sends cool air for a few minutes and then recovers. A reversing valve stuck in cooling, or a thermostat configured for the wrong valve type, cools continuously while calling for heat. Low refrigerant charge or a failed compressor gives air that is neither warm nor cold. The first is normal; the other two need a technician.
Who looks after the loop on a water-source heat pump system?
Usually the building owner or condo corporation maintains the loop, the boiler, the heat-rejection equipment and the pumps, while the unit above your ceiling may be yours under the lease or the declaration. Check the document before paying for a repair. We service the units and report loop temperature and flow readings to the property manager when the loop is the cause.
Is it worth repairing a heat pump that uses R-410A?
Usually yes if the compressor and coils are sound, since R-410A is still available for service and common parts are stocked. The picture changes with a failed compressor or a leaking coil on a unit over 12 to 15 years old: at that point the repair is a large share of a new unit's cost, and new equipment uses a newer refrigerant. We price both so the decision is made on numbers.
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One licensed team for installs, maintenance contracts and 2 AM calls.