Our technicians are trained and certified to repair central ducted heat pump systems from all major manufacturers. Whether we installed your system or not, we'll repair it. Brands we service include:

• Lennox
• Daikin
• Bosch
• American Standard
• Carrier
• Trane
• Bryant
• Goodman
• York
• Rheem
• Armstrong Air
• And most other residential and light commercial central heat pump brands

Our technicians carry a comprehensive inventory of common parts for the most popular brands, which means fewer return visits and faster resolutions on the first call.

Because a ducted heat pump serves your entire home through a single system, problems tend to be felt everywhere at once — making them harder to ignore but also easy to misdiagnose without the right equipment. Here are the warning signs to watch for:

No Heating or No Cooling Throughout the Home

If your system is running — you can hear the outdoor unit operating and the air handler blowing — but the air coming through your vents is not heated or cooled, the problem likely lies in the refrigerant circuit or the reversing valve. A refrigerant leak, a failed reversing valve, a stuck expansion valve, or a compressor issue can all cause the system to run without producing any meaningful temperature change. This is the most common emergency call we receive for central heat pump systems and has several possible causes, all of which our technicians can diagnose on the first visit.

System Blowing Cold Air in Heating Mode

If your heat pump is in heating mode but your vents are delivering cold or room-temperature air, the most likely culprits are a refrigerant issue, a reversing valve stuck in cooling position, a failed defrost control board, or a problem with the outdoor unit's ability to extract heat from the air. In a dual-fuel system, this may also indicate that the heat pump is failing to activate and the furnace backup has taken over — or conversely, that the gas furnace is not switching on when the heat pump cannot keep up. Our technicians diagnose both components of a dual-fuel system.

System Won't Turn On at All

A completely unresponsive system — no outdoor unit activity, no air handler blowing, no thermostat response — points to an electrical issue. Common causes include a tripped circuit breaker, a blown fuse in the disconnect box near the outdoor unit, a failed contactor or capacitor, a failed control board, or a wiring fault between the thermostat and the air handler or outdoor unit. In a dual-fuel system, thermostat wiring faults can cause both the heat pump and the furnace to stop responding simultaneously. Check your breaker panel first, but if resetting the breaker doesn't resolve the issue, call us — repeatedly tripping breakers is itself a symptom that needs investigation.

Outdoor Unit Iced Over

Some frost on the outdoor coil during cold weather operation is entirely normal — your heat pump runs a brief automatic defrost cycle every 30 to 90 minutes to clear it. What is not normal is heavy ice accumulation that builds up and doesn't clear, or ice forming on the refrigerant lines or on the outdoor coil body itself. This typically indicates a defrost control failure, a faulty defrost sensor or thermostat, a refrigerant charge issue, or severely restricted airflow across the outdoor coil due to debris or damage. Heavy icing left unaddressed will eventually prevent the outdoor coil from functioning and can damage the compressor.

Weak or Uneven Airflow Through Vents

If some rooms are receiving normal airflow but others are getting very little, the problem is more likely in the duct system than the heat pump itself — a disconnected duct, a closed or blocked damper, or a duct that has collapsed. If airflow is weak throughout the entire home, the indoor air handler's blower motor may be failing, the filter may be severely clogged (always check this first), or the evaporator coil may be frozen due to a refrigerant or airflow issue. Reduced airflow is often a gradual problem that homeowners adapt to without realizing how much comfort and efficiency they're losing — a technician visit will reveal the cause.

Unusual Noises from the Outdoor Unit or Air Handler

A properly functioning ducted heat pump operates at a low, consistent noise level. New or changed sounds are worth paying attention to:

• Loud banging or clanking from the outdoor unit: Usually indicates a loose or broken component — a fan blade that has come loose, a failing compressor with internal mechanical damage, or a loose mounting bracket. Shut the outdoor unit off and call us promptly if you hear this.
• Squealing or grinding from the air handler: Points to a failing blower motor bearing — the motor that drives your indoor fan. This will worsen quickly and should be addressed before the motor seizes.
• Rattling from supply registers or return grilles: Often caused by loose register covers, debris in the ductwork, or a loose panel on the air handler cabinet. Usually minor but worth investigating.
• Hissing or bubbling from the refrigerant lines: Strongly suggests a refrigerant leak. These sounds occur when gas escapes through a small leak under pressure. A refrigerant leak requires immediate professional attention — it is not a problem that resolves on its own.
• Clicking that doesn't stop: Persistent clicking during startup or operation usually points to a failing relay, contactor, or control board. Normal systems click briefly at startup and shutdown.

Heat Pump Cycling On and Off Frequently

Short cycling — when the system turns on, runs briefly, then shuts off before reaching the set temperature — is hard on the compressor and results in poor comfort and dehumidification. In a ducted system, short cycling can be caused by an oversized system (a sizing error from the original installation), a refrigerant problem, a dirty or clogged filter restricting airflow, a failing compressor running hot and triggering its thermal protection, or a faulty thermostat. If your system has always short-cycled, the cause may be from installation. If it's a new behaviour, something has changed or failed.

Heat Pump Running Constantly Without Reaching Set Temperature

If your system runs continuously but your home never reaches the thermostat setting, there are several possible explanations. In very cold Ontario weather, it is normal for a heat pump to run more or less continuously to maintain temperature — this is expected behaviour, not a fault. However, if the system is running constantly in mild weather, or if it used to reach set temperature comfortably and now cannot, the likely causes are a refrigerant charge issue, dirty coils restricting heat transfer, a failing compressor, or duct leakage that has worsened. In a dual-fuel system, the gas furnace should be assisting at this point — if it isn't activating, the dual-fuel control setup may need attention.

Water Pooling Around the Air Handler

The indoor air handler produces condensation during cooling operation, which drains away through a condensate drain line. If water is pooling around the base of the air handler or dripping from the unit, the condensate drain line is blocked, the drain pan is cracked or misaligned, or the evaporator coil is freezing and then thawing faster than the drain can handle. Water damage from a blocked condensate drain can be significant — finished ceilings, flooring, and building materials around the air handler are all at risk. Address this promptly.

Burning Smell or Electrical Odour

Any burning smell coming from the air handler or from your supply vents should prompt an immediate shutdown of the system at the thermostat and the breaker. A burning smell typically indicates an electrical fault — an overheating motor, a failing capacitor, a wiring issue, or in rare cases a more serious electrical problem. Do not restart the system until a technician has inspected it. A musty or mouldy smell is less urgent but indicates mould growth on the evaporator coil or in the air handler, which affects indoor air quality and should be addressed at your next service visit.

Error Codes on the Thermostat or Air Handler

Most modern ducted heat pump systems communicate fault information through error codes displayed on the thermostat, the air handler control board, or both. These codes vary by brand and model but are designed to direct technicians to the source of the fault quickly. If your thermostat is displaying an error code or your air handler is showing a flashing LED pattern, note exactly what it says or photograph it before resetting the system, and share that information when you call us. It meaningfully speeds up diagnosis.

Our technicians handle the full range of central heat pump repairs, including:

• Refrigerant leak detection and repair: We use electronic leak detection equipment to locate the source of a leak precisely, repair it at the point of failure, and recharge the system to manufacturer specifications. Adding refrigerant without finding and fixing the leak is not a proper repair.
• Compressor repair and replacement: The compressor is the most critical and most expensive component in a central heat pump. When a compressor fails, we provide an honest assessment of whether repair or replacement is economically justified, and we present all options clearly.
• Reversing valve replacement: A failed or stuck reversing valve locks the system in heating or cooling mode — or prevents operation entirely. Reversing valve replacement requires full refrigerant recovery, valve replacement, evacuation, and recharge.
• Expansion valve replacement: A failed thermal expansion valve or electronic expansion valve disrupts refrigerant flow and causes poor heating or cooling performance, icing, or compressor damage over time.
• Blower motor replacement: The indoor air handler blower motor drives airflow through your duct system. A failing motor causes reduced airflow, overheating, or complete system shutdown. We replace both the motor and associated capacitors.
• Condenser fan motor replacement: The outdoor condenser fan motor is essential for heat rejection in cooling mode and heat absorption in heating mode. Failure causes system shutdown via high-pressure protection.
• Defrost control board and sensor replacement: A failed defrost system causes the outdoor coil to ice over in cold weather, severely reducing heating capacity. We replace defrost control boards, defrost thermostats, and defrost sensors.
• Control board replacement: Both the air handler control board and the outdoor unit control board can fail, causing a wide range of symptoms. We carry common boards for major brands and can typically complete replacement on the first visit.
• Capacitor and contactor replacement: These are common electrical wear items in the outdoor unit. A failed start or run capacitor prevents the compressor or outdoor fan motor from starting. A failed contactor prevents the outdoor unit from receiving power.
• Condensate drain cleaning and repair: We clear blocked condensate lines, clean drain pans, repair or replace cracked pans, and install condensate safety switches where appropriate to prevent future water damage.
• Evaporator and condenser coil cleaning: Dirty coils are a major cause of reduced system efficiency and icing. Professional coil cleaning restores heat transfer capacity and is one of the highest-impact maintenance interventions available.
• Thermostat and dual-fuel control diagnosis and replacement: Thermostat faults, incorrect dual-fuel control settings, and wiring errors between the thermostat and system components can cause a wide range of behaviours that appear to be equipment failures. We diagnose and resolve control system issues for all thermostat types including smart thermostats and dual-fuel controllers.
• Duct system fault diagnosis: We distinguish between heat pump equipment faults and duct system problems — disconnected ducts, failed dampers, and severe duct leakage can mimic heat pump failure symptoms. When the duct system is the problem, we identify it and provide repair options.
• Dual-fuel system switchover diagnosis: In dual-fuel systems, the interaction between the heat pump and the gas furnace introduces additional points of potential failure — control wiring, lockout relay operation, and outdoor temperature sensor function. We diagnose the complete dual-fuel system, not just one component.

When you call Constant Home Comfort for a ducted heat pump emergency, here is exactly what happens:

1. Call us anytime — 24 hours a day, 7 days a week: Our dispatch team takes your call, gathers information about what the system is doing or not doing, and gets a technician dispatched to your location. We cover all of Ontario year-round, including holidays.

2. Fast response across Ontario: We serve Toronto, the GTA, Hamilton, Ottawa, London, Barrie, Waterloo, Burlington, and surrounding communities. Our technicians are distributed across the province to minimize response times to every service area.

3. First-visit diagnosis with the right tools: Our technicians arrive equipped with professional refrigerant gauges, manifold sets, leak detection equipment, electrical diagnostic tools, and a comprehensive parts inventory for major brands. We diagnose correctly on the first visit.

4. Clear explanation and upfront pricing before any work begins: We explain exactly what we found, what repair is needed, and what it will cost — before we touch anything. You approve the repair, then we proceed. No surprises on the invoice.

5. Quality repair backed by our workmanship warranty: Every repair we perform is backed by our workmanship warranty. If a covered repair fails after our visit, we stand behind it.

Not every breakdown calls for a repair. When the cost of a repair approaches the cost of replacement, or when the system has a history of recurring problems, replacement is often the smarter financial decision. Here is a clear framework:

• Repair is generally the right choice when: The system is less than 10 years old, the repair cost is less than half the installed cost of a comparable new system, the failure is in a non-compressor component, and the system has been reliable with no pattern of recurring issues.
• Replacement is worth serious consideration when: The system is 12 to 15 or more years old, the compressor has failed, the repair cost exceeds half the cost of a new installation, the system has had multiple significant repairs in a short period, or the system's efficiency rating is significantly below what today's equipment delivers.

Our technicians will always give you an honest recommendation. If a repair is the right call, we'll fix it. If replacement is the better investment, we'll tell you so plainly — and we'll explain the current options, available rebates, and financing plans so you can make an informed decision on the spot or take time to consider without pressure.

The overwhelming majority of central heat pump breakdowns are traceable to issues that develop gradually over time — dirty coils, degraded electrical contacts, low refrigerant from a slow leak, a defrost sensor drifting out of spec. A trained technician catches these developing problems during a scheduled annual visit, before they cause a complete system failure on the coldest night of the year.

Constant Home Comfort offers preventive maintenance plans that include annual professional tune-ups, priority emergency dispatch, and discounted parts and repairs. For a central ducted system that is responsible for whole-home comfort, a maintenance plan is not optional — it is the single most effective way to protect your investment and avoid emergency repair costs.

If you're calling us for a repair, ask about our maintenance plan options. Many customers who experience an unexpected breakdown enrol in a maintenance plan immediately afterward — because they'd rather pay for prevention than for another emergency call.

Constant Home Comfort provides 24/7 central ducted heat pump repair across Ontario, including:

• Toronto and all inner-city neighbourhoods
• North York, Etobicoke, and Scarborough
• Vaughan, Richmond Hill, Markham, and Thornhill
• Mississauga, Brampton, and Oakville
• Durham Region — Oshawa, Whitby, Ajax, and Pickering
• Newmarket, Aurora, and King City
• Hamilton and Burlington
• Waterloo Region — Kitchener, Waterloo, and Cambridge
• London and surrounding areas
• Ottawa and Kanata
• Barrie and Simcoe County
• And all communities across Ontario — call us to confirm service availability in your area

My ducted heat pump is in heating mode but blowing cold air. What's wrong?

This is one of the most common complaints we receive. The most likely causes are a refrigerant issue reducing the system's ability to extract heat from outdoor air, a reversing valve stuck in cooling position, a defrost system failure causing ice buildup on the outdoor coil, or a compressor problem. In some cases, the system may have switched to emergency heat mode or the thermostat may be set incorrectly. A technician needs to diagnose the specific cause — there is no reliable way to self-diagnose this over the phone.

My heat pump is running but the house isn't warming up. Should I switch to emergency heat?

Emergency heat (or auxiliary heat) bypasses the heat pump and runs electric resistance heating coils inside the air handler directly. It is significantly less efficient than heat pump operation and should only be used as a genuine temporary measure while waiting for a repair. If your system has a gas furnace as backup in a dual-fuel configuration, it should be switching to gas automatically when the heat pump cannot keep up — if it isn't, that's also worth a service call. Use emergency heat if you need it, but call us to get the heat pump diagnosed and repaired promptly.

How quickly can you respond to an emergency call?

Response times vary by location and time of call, but our priority is always speed. In most GTA communities and major Ontario cities, we aim to have a technician on-site within a few hours of your call. Our dispatch team will give you an estimated arrival window when you phone in. For maintenance plan members, emergency dispatch is prioritized over standard service calls.

My system was working fine yesterday. Could the problem just be the thermostat?

Yes — a faulty thermostat, dead thermostat batteries, incorrect thermostat settings, or a wiring fault at the thermostat are surprisingly common causes of apparent system failure. Before calling, check that your thermostat has power, the batteries are fresh, it is set to the correct mode (heat, cool, or auto), and the fan setting is on auto rather than on. If all of that looks correct and the system still doesn't respond, call us — the thermostat itself may have failed, or the problem may be deeper in the system.

Can you repair a ducted heat pump you didn't install?

Absolutely. We repair central heat pump systems from all major brands regardless of who originally installed them. Our technicians are brand-agnostic and carry diagnostic equipment and common parts for all major manufacturers. The only requirement is that the system uses standard refrigerant and conventional components — which all modern residential systems do.

What should I do while waiting for a technician?

Check that the circuit breaker for the heat pump hasn't tripped — the outdoor unit and the air handler are typically on separate breakers, and both need to be on. Check the filter in the air handler and replace it if it's clogged, as a severely restricted filter can cause the system to shut down on safety. Set the thermostat to a moderate temperature and leave it there. If the system is making loud or unusual noises, or if you smell burning, turn it off at the thermostat and at the breaker and leave it off until our technician arrives.

When your central heat pump fails, your whole home feels it. Don't wait it out — our certified technicians are available 24 hours a day, 7 days a week, ready to diagnose and repair your system as fast as possible. Whether your system is blowing cold air in January, not cooling in July, or simply refusing to start, we have the tools, the parts, and the expertise to fix it right the first time.

Call us now: 1 (888) 675-5907

Visit: constanthomecomfort.com

Serving Toronto, GTA, Hamilton, Ottawa, London, Barrie, Waterloo, Burlington, and all of Ontario — around the clock.