Tempstar Furnace operating cost & efficiency in Greater Vancouver
A furnace bill is mostly a house bill. Two identical Tempstar units, one in a 1958 Burnaby bungalow with original windows and one in a 2019 Langley townhouse, will post wildly different gas usage all winter. Same equipment. Different envelope.
That matters because homeowners usually shop the wrong variable. They compare efficiency ratings between models and ignore the duct system, the filter, the thermostat schedule and whether the furnace was sized correctly when it went in. Those four are where the money hides.
What follows is how a technician reasons about running cost while standing in your mechanical room. Not marketing math. The order things get checked, and why that order makes sense on the coast, where heating season is long, mild and wet, and the bill is built from run hours rather than deep cold snaps.
The four inputs that set your gas bill, ranked by size
Heat loss comes first. Your furnace only replaces what the building leaks, so an uninsulated crawlspace, a poorly sealed attic hatch, or single-glazed aluminum windows will dominate everything downstream of them. No efficiency tier rescues a leaky envelope.
Second is run time, which is a function of that heat loss plus your thermostat setpoint and schedule. Coastal winters rarely hit hard lows, but they sit in the range where a furnace cycles constantly for months. Hours add up quietly.
Third is combustion efficiency, expressed as AFUE. That rating tells you roughly what share of the fuel becomes usable heat over a heating season under standardized test conditions. Check your exact Tempstar model number against the manufacturer’s published spec sheet or its AHRI Directory listing. Do not rely on what a neighbour or a sales flyer says.
Fourth is electrical draw, mostly the blower, plus the inducer and controls. People forget this half entirely, then wonder why hydro climbs in January.
When we walk a house, we look at those in that order, because the fix with the best payback is often not the furnace. Sealing a return-air leak in a dusty crawlspace can move the needle more than swapping a serviceable unit. That is an unpopular answer and it is usually the right one.
Read the rating plate before you assume anything about efficiency
Open the front panel of your Tempstar and find the printed label, usually inside the burner compartment door or on the inner wall of the cabinet. It carries the full model number, the serial number, the input rating in BTU per hour, the gas type, and the electrical requirements. Photograph it. That one photo answers more questions than an hour of guessing.
Model numbers matter because a single product family can span several efficiency tiers and several cabinet widths. The letters and digits encode the input capacity and the configuration. Two furnaces that look identical from three feet away can be different animals.
With the model number in hand, pull the manufacturer’s spec sheet or search the AHRI Directory for the certified rating of your exact model, ideally as matched with your specific coil if you have air conditioning. AFUE is the seasonal rating system for gas furnaces in Canada; it is what you want for fuel comparisons.
Also note the serial number. It generally encodes manufacturing date, which tells you where the unit sits in its service life and whether any parts warranty could still apply. Warranty terms depend on registration, ownership history and the manufacturer’s own policy, so confirm coverage directly with Tempstar or through your installer rather than assuming.
Call (604) 330-3812 if you want a technician to read the plate and interpret it with you.
Single-stage, two-stage and modulating burners change the shape of your bill
A single-stage furnace has one gas rate: full. It fires hard, satisfies the thermostat quickly, and shuts off. In a mild Fraser Valley November that means short, frequent cycles, and every cycle spends fuel on warm-up and purge before it delivers useful heat.
Two-stage equipment runs most of the season on the lower fire rate and only calls the high rate when the thermostat is losing ground. Longer, gentler cycles. Air comes out of the registers less hot, but more of the time, which usually reads as fewer cold spots at the far end of the house.
Modulating burners go further, adjusting the firing rate across a range instead of two fixed points. They chase the actual load rather than overshooting it.
The efficiency gain from staging is real but it is not primarily a combustion gain. It comes from fewer start-stop losses, steadier duct temperatures and better distribution. It also depends on the thermostat being able to talk to the furnace correctly. A two-stage furnace wired to a basic single-stage thermostat may never use its low fire, which quietly erases the benefit you paid for.
If you are not sure which staging your Tempstar has, the rating plate and the control board terminal labels will tell a technician in about a minute. It is worth confirming before you spend anything on comfort upgrades.
The blower motor is the electricity half nobody budgets for
Your furnace blower can run far more hours than the burner does, especially if the fan is set to continuous circulation or if the system also handles summer cooling. That motor is on your hydro bill, not your gas bill, which is why the cost stays invisible until you compare a winter statement to a summer one.
Older furnaces commonly use a PSC motor, a fixed-speed design that draws roughly the same power regardless of how hard the ducts fight back. Newer designs use an ECM, an electronically commutated motor that can vary speed and, in constant-airflow versions, hold a target airflow while adjusting its own power draw.
Here is the part that surprises people: a variable-speed motor in a restricted duct system does not save you money. It works harder to hit its airflow target and the draw climbs. The motor obeys; the ductwork wins. Fix the restriction first.
Practical checks a technician runs: measured external static pressure across the furnace, filter condition and filter type, blower wheel cleanliness, and whether the speed tap or airflow setting matches the equipment and the house. A blower wheel caked with dust from an old renovation moves less air at the same power, which shows up as long run times and rooms that never quite warm.
Clean wheel, correct airflow setting, sane filter. That sequence, every time.
Oversizing is the quiet tax on older Lower Mainland houses
A lot of furnaces in this region were sized by rule of thumb, or by matching whatever was there before, or by adding capacity because someone once felt cold. The result is equipment that satisfies the thermostat before the house has evened out, then shuts off, then restarts a few minutes later.
Short cycling costs you in several ways at once. Each cycle includes a pre-purge, an ignition sequence, a warm-up period where flue temperatures are still climbing, and a post-purge that pushes heated air out the vent. The steady-state efficiency printed on the label is measured after all that. Your furnace may spend a large share of its life never reaching steady state.
It also wears components. Igniters, inducer motors and control relays are cycle-count parts. More starts, shorter life.
The correct approach is a heat loss calculation for your actual building: insulation levels, window area and type, air tightness, orientation, and the design temperature for your municipality. That is what a Manual J style calculation does. Many homes here have had windows, insulation or a full envelope upgrade since the original furnace went in, which means the real load dropped and the equipment never followed.
If your furnace runs in bursts of a few minutes and the house still feels uneven, sizing is a genuine suspect. Ask for the calculation before anyone quotes replacement capacity.
Ducts, filters and static pressure: where good equipment goes to waste
Static pressure is the resistance your blower pushes against, and it is the single most useful number for judging whether a system will run efficiently. A technician measures it across the furnace with a manometer, then compares it to what the equipment is rated to tolerate. High readings mean the blower is straining, airflow is short, and the heat exchanger runs hotter than intended.
Common local causes: a one-inch filter slot stuffed with a very high-restriction pleated filter, undersized or crushed flex duct in a tight crawlspace, closed or blocked registers, a return path that relies on a floor cavity that leaks into the crawlspace, and duct runs added during a basement suite conversion without any recalculation.
Leakage is the other half. Supply ducts leaking into an unconditioned crawlspace or attic are heating a space you do not live in. Return leaks are worse in one specific way: they pull in cold, damp, sometimes dusty crawlspace air and mix it into what you breathe.
What to do about it in order: replace or right-size the filter, open and clear registers, seal accessible joints with mastic or approved foil tape, straighten or replace kinked flex, then re-measure. Duct cleaning alone rarely changes efficiency; sealing and sizing do.
This work is measurable. Ask for before and after static pressure readings rather than taking anyone’s word for the improvement.
Condensing versus non-condensing, and what coastal damp does to venting
Higher-efficiency furnaces extract enough heat from the flue gases that water vapour condenses, which is why they vent through plastic pipe out a sidewall and produce a steady trickle of acidic condensate. Mid-efficiency units vent hot, dry flue gas through metal, usually up a chimney liner.
That distinction drives real operating issues here. Condensate needs a route to a drain, a trap that is actually holding water, and protection from freezing where the line runs through an unheated crawlspace or garage. A blocked or frozen condensate path trips the safety and shuts the furnace down, typically on the coldest morning of the year.
Sidewall terminations collect their own problems: shrubs grown in around them, snow drift, lint from a nearby dryer vent, or two terminations placed so the exhaust of one gets pulled into the intake of another. Any of those degrade combustion and can trip a pressure or vent safety.
Salt air near the water and persistent winter damp accelerate corrosion on metal venting and on outdoor components generally. If your Tempstar vents into an older masonry chimney, the liner condition deserves a look, because a deteriorated liner is both an efficiency issue and a safety one.
If you ever smell gas or a CO alarm sounds, leave the house, then call the gas utility and a licensed technician from outside. Never tape over, jumper or bypass a safety lockout to keep heat running.
What actually lowers the bill, and what only feels like it does
Things with measurable return: correct filter selection changed on a real schedule, a clean blower wheel, sealed and properly sized ducts, a burner and heat exchanger cleaned during annual service, a thermostat programmed to your household’s real occupancy, and combustion checked with an analyzer so the burner is running where the manufacturer intended.
Things that mostly do not: closing vents in unused rooms, which raises static pressure and works against you; cranking the thermostat higher to warm the house faster, since a single-stage furnace has one output either way; and swapping a serviceable furnace purely to chase a slightly higher efficiency number while the ducts stay untouched.
Setbacks work in this climate, with a caveat. Deep overnight setbacks in a poorly insulated house can produce a long, hard recovery in the morning. Modest, consistent setbacks with a scheduled recovery time usually beat aggressive swings.
On the envelope side, air sealing and crawlspace or attic insulation almost always outperform equipment changes per dollar. Provincial and utility programs through CleanBC and FortisBC change over time and have their own eligibility rules and paperwork, so check current program terms directly rather than relying on anything you read secondhand.
HeatLand has served Metro Vancouver and the Fraser Valley since 1999, TSBC certified for gas work. Call (604) 330-3812 for a free written, no-obligation estimate.
Quick Checklist
- Photograph the rating plate inside the furnace door: full model number, serial, and BTU input rating
- Look up your exact model’s AFUE on the manufacturer spec sheet or the AHRI Directory, not from memory
- Confirm whether your unit is single-stage, two-stage or modulating, and whether the thermostat can drive it
- Check the filter: right size, right restriction level, and actually changed on schedule
- Open every supply register and clear returns of furniture, rugs and storage
- Have external static pressure measured across the furnace and compared to the equipment’s rated limit
- Inspect condensate drain and vent terminations for blockage, freezing, or intake-exhaust recirculation
- Book annual combustion service and ask for the analyzer readings in writing
| Cost driver | What it changes | Homeowner or technician |
|---|---|---|
| Building heat loss | Total run hours all winter | Technician calculation; homeowner does air sealing and insulation |
| Burner staging | Cycle length and start-stop losses | Technician confirms staging and thermostat compatibility |
| Blower motor type and setting | Electrical draw during every run hour | Technician sets airflow; homeowner keeps filter clean |
| Duct sizing, leakage and static pressure | Delivered heat versus heat produced | Technician measures and seals; homeowner clears registers |
| Furnace sizing versus real load | Short cycling and component wear | Technician performs heat loss calculation |
| Vent and condensate condition | Safety lockouts and combustion quality | Technician inspects; homeowner keeps terminations clear |
Frequently Asked Questions
How do I find the efficiency rating of my specific Tempstar furnace?
Open the front panel and photograph the rating plate, which carries the full model and serial number. Then look that exact model up on the manufacturer’s published spec sheet or in the AHRI Directory. AFUE is the seasonal rating system used for gas furnaces in Canada. Do not rely on a general figure for the brand, because one product family can cover several efficiency tiers and capacities.
Does running the fan continuously cost a lot?
It depends entirely on the motor. A fixed-speed PSC blower running around the clock adds meaningful hydro use, while a variable-speed ECM in a low continuous mode draws considerably less. Either way, continuous fan helps even out temperatures between floors and improves filtration. If your ducts are restricted, continuous operation amplifies that penalty, so measure static pressure before deciding.
Would a new high-efficiency furnace cut my heating bill?
Sometimes, but rarely as much as the brochure math suggests, because that math assumes the rest of the system is healthy. If your ducts leak into the crawlspace, the furnace is oversized, or the filter is choking airflow, a new unit inherits all of it. Fix airflow and sizing first, then evaluate equipment. HeatLand provides a free written estimate that spells out both paths.
Why does my furnace start and stop every few minutes?
Short cycling usually means the furnace is oversized for the current heat load, airflow is restricted, or a safety is tripping on high limit. Older homes here have often had windows and insulation upgraded since the furnace went in, dropping the real load well below the installed capacity. A technician measures temperature rise and static pressure to separate sizing from airflow before recommending anything.
Is closing vents in unused rooms a good way to save gas?
No. Closing registers raises resistance in the duct system, which makes the blower work harder, reduces total airflow, and pushes the heat exchanger toward its high limit. You may also create pressure imbalances that pull cold crawlspace air into returns. Leave supply registers open. If some rooms are genuinely unused, talk to a technician about zoning done properly instead.
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.