Tempstar Heat Pump not heating / not cooling in Greater Vancouver
The complaint usually arrives the same way. The Tempstar outdoor unit is running, you can hear it from the patio, and the house is still sitting three degrees below setpoint at nine at night. Or it is a rare hot week in Surrey and the vents are pushing air that feels like a warm breath instead of cold.
A heat pump is one machine doing two jobs. It moves heat outside in summer and pulls heat in from cold outdoor air in winter, using the same refrigerant loop run in reverse. That means a single failure can show up as “not heating,” “not cooling,” or both, depending on which way the reversing valve happens to be sitting when the part gives up. That is why the diagnostic order matters so much.
This walks through how a HeatLand technician actually works a no-heat or no-cool Tempstar call in Metro Vancouver and the Fraser Valley: what gets checked first, why that order and not another, what you can safely do before anyone comes out, and where the line is between a homeowner task and licensed work. Questions as you read? Call (604) 330-3812.
Start by deciding whether the unit is even being told to run
Before anyone touches a gauge, the first question is whether the outdoor unit is receiving a call at all. Walk to the thermostat. Confirm the mode is actually set to Heat or Cool and not Auto sitting in a deadband, and confirm the setpoint is far enough past room temperature to trigger a call — bump it four or five degrees and wait.
Then listen. Within a minute or two you should hear the indoor blower start and, shortly after, the outdoor unit. If the indoor blower runs and the outdoor unit stays silent, the problem lives between the thermostat, the low-voltage wiring, and the outdoor control board. If nothing at all happens, you are looking at power or the thermostat itself.
Check both breakers. A heat pump system has two: one for the air handler or furnace indoors, one for the outdoor unit, usually in the main panel plus a disconnect box on the wall beside the outdoor cabinet. In older Vancouver homes that disconnect is sometimes a pull-out block that has corroded loose. Also check that the air handler’s service switch, which looks exactly like a light switch near the equipment, has not been flipped off by someone working in the crawlspace.
Batteries matter more than people expect. A thermostat with dying batteries will hold a display and still drop the call intermittently, which produces the maddening “it works some days” complaint.
Airflow first, refrigerant second — and why techs refuse to flip that order
A restricted-airflow system looks exactly like a low-refrigerant system on the gauges. Suction pressure drops, the indoor coil runs cold enough to frost in cooling, head pressure sags, and an inexperienced hand starts adding refrigerant to a system that was never short. Now you have an overcharged system with a real problem underneath it.
So airflow gets confirmed first, every time. Pull the filter and look at it against a light. If you cannot see light through it, it is done. Coastal homes with pets and a lot of shoulder-season fan runtime load filters faster than people expect, and a one-inch pleated filter in a Burnaby townhouse can be finished in eight weeks.
Next is the indoor coil face. A filter that has been bypassing air around a loose frame lets a felt mat build on the upstream side of the coil, and that mat does not show up until someone opens the cabinet. Then the blower wheel itself — the fins load with dust and the wheel quietly loses a chunk of its capacity without changing the sound much.
Finally the duct side. Closed registers in unused bedrooms, a crushed flex run in a crawlspace, a filter grille sized too small for the system. Older Lower Mainland housing stock is full of ductwork that was adequate for a mid-efficiency furnace and is marginal for a heat pump that needs continuous airflow.
Ice on the outdoor coil in winter: normal, until it isn’t
Some frost on the outdoor coil during a damp Vancouver cold snap is expected. The outdoor coil is running colder than the outdoor air to absorb heat from it, and our air carries a lot of moisture, so frost forms. The unit is designed to handle that: periodically it reverses into a short defrost cycle, sends hot gas out to the outdoor coil, melts the frost, and returns to heating. You may see steam and hear a loud whoosh when the valve shifts. That is the machine working.
The failure mode is ice that never clears. A solid rind on the coil, ice bridging the fins, or a block of ice sitting in the base pan around the fan blade means defrost is not doing its job or meltwater is not draining. Common causes: a failed defrost sensor or board that never initiates the cycle, a reversing valve that will not shift, a fan that keeps running through defrost, or a blocked base pan drain that lets meltwater refreeze into a growing block.
Gutter downspouts and roof drip lines cause a surprising number of these calls here. Water falling onto an outdoor unit all winter freezes into the top of the coil regardless of how well defrost works.
Do not chip ice off with anything metal. You will puncture a coil tube and turn a control problem into a refrigerant leak. Shut the system off at the thermostat, leave the fan off, and call for service.
Warm air in cooling, cool air in heating: suspect the reversing valve
The reversing valve is the component that makes a heat pump a heat pump. It is a slide valve that redirects hot discharge gas either to the outdoor coil (cooling) or to the indoor coil (heating), and it is shifted by a small solenoid energized by the control.
When it fails, the symptom is oddly specific: the system works perfectly in one mode and does nothing useful in the other. A Tempstar that cools fine all summer and then blows air barely warmer than room temperature in November is a textbook case. The compressor runs, the outdoor fan runs, everything sounds normal, but the heat is going the wrong direction.
A technician separates the two possible causes. Either the solenoid coil is not being energized — a control, wiring, or coil failure, which is diagnosed electrically and is a comparatively straightforward repair — or the valve body itself is stuck or leaking internally between ports, which shows up as suction and discharge temperatures converging when they should be far apart. A valve that leaks internally bleeds hot gas back to the suction side and the system simply never builds capacity.
Sometimes a valve is only partially shifted, which produces a middling performance in both modes and no clean symptom at all. That one takes gauges and temperature readings at the valve body to catch. It is not something you can diagnose from the thermostat.
Outdoor unit hums but nothing spins, or trips the breaker
A hum with no rotation is a distinct sound and it points somewhere specific. The compressor or fan motor is being energized but cannot start turning. On most residential heat pumps the first suspect is the run capacitor: it stores the charge that gets the motor moving, and when it degrades the motor draws locked-rotor current, hums, heats up, and trips its internal overload after a few seconds. The unit then sits, cools down, and tries again, which is why some homeowners report it working briefly in the early morning and not at all in the afternoon.
Capacitors are cheap parts. They are also charged, and they will hold that charge after the power is off. Do not open the electrical compartment. A licensed technician discharges and tests them as routine work.
A contactor is the other frequent culprit. Its points burn and pit over years of cycling, and in our climate the whole assembly can corrode, especially on units within a few kilometres of the water in Richmond, White Rock, or along the North Shore. Salt air eats contacts and terminals.
Repeated breaker trips are a different level of concern. That can mean a shorted compressor winding, a motor drawing far past its rating, or a damaged conductor. Do not keep resetting a breaker that trips again. It is protecting the wiring in your walls, and repeatedly forcing it closed on a fault is genuinely dangerous.
Reading fault codes and lights without guessing at meanings
Most modern Tempstar outdoor and indoor controls will flash a diagnostic code on an LED, and some models display it on a small digit readout on the board. Before you power-cycle anything, write down exactly what you see: the colour of the light, the flash pattern, the pause between groups, and which board it is on. Power-cycling clears the code and erases the best clue you have.
Here is the part people get wrong. Code meanings are not universal. The same flash pattern means different things across brands, across model families within a brand, and across production years within a model. Never rely on a meaning you found on a forum for a different unit.
Read the code off your unit and verify it against that unit’s own manual, or the diagnostic legend printed on the label inside the service panel or cabinet door. That legend is the authority for your equipment. If you no longer have the manual, the model and serial plate on the outdoor cabinet will let a technician pull the correct documentation.
What codes generally tell you is a category, not a part: something in the ignition or auxiliary heat path, something in pressure or airflow, a limit or overheat condition, a flow or sensor fault, a communication fault between indoor and outdoor controls, or a compressor protection lockout. The category narrows where to test. It does not replace testing.
Auxiliary and backup heat: the reason your bill spiked instead of your house going cold
Not every failed heat pump announces itself with cold air. Many Greater Vancouver systems pair a Tempstar heat pump with electric resistance strips in the air handler or with a gas furnace in a dual-fuel setup. When the heat pump side fails, the backup takes over and the house stays comfortable. The only symptom is a hydro or gas bill that jumps hard, and possibly an “Aux Heat” or “Em Heat” indicator on the thermostat that you never noticed before.
This is worth catching early. Resistance heat costs substantially more to run than a working heat pump does for the same comfort, and a system can limp along on backup for an entire winter while nobody investigates.
Check your thermostat for an auxiliary indicator during normal operation. Brief aux use during a deep cold snap or right after a big setpoint recovery is expected behaviour. Continuous aux operation at five degrees outside is not — a healthy heat pump does most of the work at Lower Mainland winter temperatures.
Also confirm nobody left the thermostat in Emergency Heat mode. That setting locks out the heat pump entirely and runs backup only. It exists for the case where the outdoor unit is known to be broken, and it gets left on by accident constantly.
If your backup is a gas furnace and you ever smell gas or a CO alarm sounds, leave the home first and call the gas utility and a licensed technician from outside.
What HeatLand does on site, and what it costs to find out
A proper diagnosis on a Tempstar heat pump follows the order above and produces evidence, not a guess. The technician confirms the call and the voltage, verifies airflow and static pressure, reads the fault code off your board against your unit’s own legend, checks capacitors and contactor under load, then puts gauges on and takes line temperatures to evaluate the refrigerant circuit and reversing valve. Only then does anyone talk about parts.
We are a family-run, licensed and insured contractor serving Metro Vancouver and the Fraser Valley since 1999, with TSBC-certified gas fitting for dual-fuel systems. We service all major brands. If the repair turns into a replacement conversation, financing is available.
What a repair costs depends on real variables, not a number off a website: which component failed, whether the sealed system has to be opened, refrigerant recovery and evacuation time, accessibility of the outdoor unit, electrical condition at the disconnect, whether ductwork or airflow work is needed to make the fix hold, and whether permits apply. You get a free written no-obligation estimate before any work begins.
Strata owners: outdoor unit placement and noise limits are usually governed by your bylaws, and replacement often needs council approval. Bring us in before you submit paperwork so the application matches what will actually be installed.
Call (604) 330-3812.
Quick Checklist
- Confirm the thermostat is in Heat or Cool (not Auto or Emergency Heat) and push the setpoint 4-5 degrees past room temperature to force a call.
- Replace the air filter and check that no return or supply registers are closed or blocked.
- Verify both breakers — indoor air handler and outdoor unit — plus the outdoor disconnect and the service switch near the equipment.
- Change the thermostat batteries if it takes them; a weak battery drops the call intermittently and mimics an equipment fault.
- Clear leaves, grass clippings, snow and anything stacked within about two feet of the outdoor unit, and redirect any downspout or roof drip landing on it.
- Write down the exact LED flash pattern on the control board before power-cycling, and check whether the thermostat shows Aux or Em Heat during normal running.
| What you notice | Most likely area | Homeowner or licensed tech |
|---|---|---|
| Weak airflow at every vent, in both heating and cooling | Filter, indoor coil, blower wheel or duct restriction | Filter is yours; coil, blower and ducts are tech work |
| Cools fine in summer, blows barely-warm air in winter | Reversing valve or its solenoid circuit | Licensed tech — sealed-system and control diagnosis |
| Outdoor unit hums, fan or compressor will not spin | Run capacitor, contactor, or motor fault | Licensed tech — stored charge, do not open the panel |
| Thick ice on the outdoor coil that never melts | Defrost control or sensor, blocked base-pan drain, water dripping on the unit | Shut it off and call — never chip ice off a coil |
| House stays comfortable but the bill jumps sharply | Heat pump failed and backup or Em Heat is carrying the load | Check the thermostat mode yourself, then call for diagnosis |
Frequently Asked Questions
Is it normal for my Tempstar heat pump to steam and make a loud whoosh in winter?
Yes. That is the defrost cycle. The unit briefly reverses to send hot gas out to the outdoor coil and melt accumulated frost, then switches back to heating. The whoosh is the reversing valve shifting and the steam is melted frost evaporating. It should last a few minutes and leave the coil clear. If the coil stays iced after the cycle, or ice keeps building in the base pan, that is a fault worth a service call.
Why is my heat pump blowing cool air when it is set to heat?
Air from a heat pump in heating mode is normally warm but not furnace-hot, so some homeowners mistake normal operation for a fault. Genuinely cool air points elsewhere: the reversing valve stuck in cooling, low refrigerant charge from a leak, a compressor not running while the blower does, or a defrost cycle you happened to catch. If it is cool at every register for more than a few minutes at a time, have it diagnosed rather than raising the setpoint.
Can I add refrigerant to my heat pump myself?
No. Refrigerant handling requires certification, the equipment is under pressure, and low charge is a symptom rather than a cause — refrigerant does not get consumed, so if the system is short there is a leak somewhere that needs finding and repairing. Topping up without locating the leak wastes money and puts the compressor at risk. It also looks identical to a restricted-airflow problem, which is why airflow is verified before anyone touches a gauge.
Should I run Emergency Heat when the heat pump is not working?
Only as a short-term measure while you wait for service, and only if your home is genuinely too cold. Emergency Heat locks out the heat pump and runs backup heat exclusively, which is far more expensive to operate. Turn it off once the system is repaired — a thermostat left in Em Heat is one of the most common reasons for a surprise winter bill. Book service rather than living on backup for weeks.
Does salt air near the water actually damage a heat pump?
It does. Homes close to the water in Richmond, White Rock, Tsawwassen and along the North Shore see accelerated corrosion on outdoor coil fins, cabinet fasteners, contactor terminals and electrical connections. Corroded fins lose heat-transfer capacity and corroded contacts cause intermittent no-start faults. Regular rinsing of the outdoor coil with plain water and a maintenance visit that includes cleaning and tightening electrical connections meaningfully extends equipment life in these areas.
How efficient should my Tempstar heat pump be, and does that affect my problem?
Heat pump efficiency is rated using SEER2 for cooling and HSPF2 for heating, with COP sometimes cited for heating performance at a given outdoor temperature. Look up the figures for your exact model on the manufacturer’s spec sheet or the AHRI directory rather than assuming. Efficiency ratings matter for operating cost and for CleanBC or FortisBC program eligibility, but a rating does not diagnose a fault — a high-efficiency unit with a stuck reversing valve still will not heat.
Reviewed by the HeatLand Heating & Cooling team — licensed, insured, TSBC-certified HVAC contractor serving Metro Vancouver & the Fraser Valley since 1999. Error codes, specifications, pricing and rebate programs vary by model and change over time; confirm details against your unit’s own manual, a written quote, and the manufacturer or CleanBC/FortisBC. If you smell gas or your CO alarm sounds, leave the home and call the gas utility and a licensed technician from outside.