Alberta · Energy · checked September 28, 2026

Combustion safety testing in Lethbridge

A combustion safety test checks that your furnace, water heater and fireplace vent their exhaust outside instead of into the house, which matters most right before and after you tighten the house up. In the Lethbridge area, the main heating energy is natural gas for 81% of households.

Get matched in Lethbridge → The combustion safety and spillage check
A gloved hand inserting a combustion analyzer probe into a furnace flue pipe in a basement

Cost

Included with an evaluation

Natural gas heat

81%

Homes whose furnace must vent safely

Gas distributor

ATCO Gas

CO alarms required (existing homes)

No

Install them anyway: they are the backstop

How Lethbridge is built

Lethbridge's houses by when they were built Ten house shapes, one for each tenth of Lethbridge's 33,945 houses. Before 1961: 19%, 1961–1990: 35%, 1991–2000: 11%, 2001 or later: 35%. Older houses glow hotter.
  • Before 1961 19%
  • 1961–1990 35%
  • 1991–2000 11%
  • 2001 or later 35%
Each house stands for one in ten of Lethbridge's 33,945 houses (single-detached, semi-detached, row and duplex), drawn by when it was built. The glow shows the usual pattern: older houses tend to be leakier and less insulated. More snow in the drawing means more heating degree-days: a longer, colder heating season. Sources: Statistics Canada 2021 Census (table 98-10-0233-01), NRCan HOT2000 climate data.

Why it matters in Lethbridge

In the Lethbridge area, 91% of households heat mainly with a forced-air furnace; natural gas is the main heating energy for 81% of households (Statistics Canada, 2023).

The risk rises after air sealing: a tighter house plus a strong exhaust fan or dryer can pull exhaust back down a chimney. That's why advisors test for spillage during an evaluation and why it should be repeated after serious tightening.

The CO alarm rule in Alberta

Alberta requires CO alarms in new homes with a fuel-burning appliance or attached garage; for existing homes the province calls them highly recommended rather than mandatory.

What the check involves

  • Worst-case depressurization: exhaust fans and the dryer on, doors set to make the appliance room as negative as it gets.
  • A spillage and draft check at each appliance, with a CO reading.
  • A plan if anything fails: often a sealed-combustion appliance or a fix to the venting, done by a licensed gas or oil technician.

The combustion safety check in detail.

Prairies Alberta, Saskatchewan and Manitoba

What this means in Lethbridge’s climate

Long, very cold, very dry winters: air sealing, radon testing and humidity balance lead.

Why it matters here: Checks that gas furnaces and water heaters vent safely in a tighter house.

Best timing: During the blower door visit, especially after air sealing.

  • Check gas appliances after tightening. Most homes here burn natural gas. Air sealing can depressurize the house and pull exhaust back inside, so appliances need a combustion safety test and working CO alarms. Ask: Ask for a combustion safety test during the blower door visit, and again after air sealing.

What else homes in Lethbridge need →

Sources for this climate guide · checked October 26, 2026

NRCan-licensed service organizations serving Lethbridge

A service organization is a company that Natural Resources Canada (NRCan) licenses to deliver EnerGuide evaluations; its registered energy advisors do the home visit. Energy advisors check for combustion spillage during an evaluation; fixing a venting problem is work for a licensed gas or oil technician.

Source: NRCan list of licensed service organizations, checked September 28, 2026. Call to confirm your street is covered and ask about wait times.

Programs in Lethbridge

Provincial · needs an evaluation Clean Energy Improvement Program (Alberta) Property-tax financing in 27 Alberta municipalities, with an EnerGuide evaluation required; Calgary is closed until winter 2026/27 and Edmonton is waitlisting Open · deadline

Combustion safety test in Lethbridge: common questions

Are CO alarms required in Lethbridge homes?

Alberta requires CO alarms in new homes with a fuel-burning appliance or attached garage; for existing homes the province calls them highly recommended rather than mandatory.

Who does combustion safety testing?

Energy advisors check for spillage during an EnerGuide evaluation. Repairs to venting or appliances are done by a licensed gas or oil technician.

I have CO alarms. Isn't that enough?

Alarms warn you once CO is already in the house. A spillage test finds a venting problem before it produces CO.

Combustion safety test near Lethbridge

Combustion safety test in Calgary177 kmCombustion safety test in Red Deer296 kmCombustion safety test in Sherwood Park427 kmCombustion safety test in Edmonton433 kmCombustion safety test in Kelowna475 km All 70 cities →

Sources

Checked September 28, 2026. Census figures are for the municipality (Alberta); climate data is NRCan's HOT2000 station Lethbridge (4 km away).

Get matched with a registered advisor in Lethbridge

Tell us your postal code and what you’re planning. We’ll connect you with one licensed service organization serving your area. No spam, no shared lead lists.

By submitting you agree we may share your request with one registered service organization serving your area. Participating advisors pay us a referral fee — you pay nothing, and it never affects the directory. See our privacy note.