Anthony — TSSA-Certified G1 Gas Technician
TSSA G1 licence #TBD · 15+ years in gas and mechanical trades · Service area: Greater Toronto Area, Ontario
Last updated: 2026-08-03
Why do so many Ajax furnaces get tagged for the same reason?
Because Ajax grew in concentrated construction waves, a large share of homes south of Taunton Road were fitted with furnaces from the same era, sometimes the same production run. When a heat exchanger design common to that era begins reaching its typical failure age, technicians often find cracked heat exchangers across an entire neighbourhood within a short window.
A cracked heat exchanger is treated as an immediate hazard because it can allow combustion gases, including carbon monoxide, to mix with the household air supply. This results in an automatic Type A tag, and unlike a venting correction, a cracked heat exchanger cannot be repaired — the furnace has to be replaced.
Why do orphaned water heaters get tagged so often in Ajax?
Rental water heaters in Ajax have frequently been replaced multiple times over twenty or more years by different contractors, and each swap can leave small deviations from code that accumulate: a vent connector installed at the wrong rise, a missing drip leg, or a shared chimney that stops functioning correctly once the appliance sharing it upgrades to sidewall venting.
When a furnace beside a water heater is replaced with a high-efficiency sidewall-vented unit, the water heater is often left alone in a chimney sized for two appliances. Its combustion output alone is not enough to establish draft, especially on a mild day, and the resulting spillage is one of the most common causes of Type A tags in Ajax.
What does a technician do differently for a heat exchanger failure versus a vent defect?
A vent or piping defect is typically a single-visit correction: the technician identifies the fault, corrects the venting or piping, and re-tests. A cracked heat exchanger requires an honest conversation about the appliance's remaining service life, since the correction is a full furnace replacement rather than a repair.
In either case, documentation of the correction and the tests performed is provided, which matters for landlords, property managers, and insurers who need proof the appliance was returned to service by a licensed technician.
How quickly can a red tag be resolved in Ajax?
Photo triage — the tag, the appliance, the data plate, and the venting — usually produces an accurate quote the same day and often identifies whether the issue is a straightforward correction or a replacement before anyone drives to the property. For rental properties, mentioning that there is no heat moves the request ahead of routine maintenance calls.
Frequently asked questions
Can a cracked heat exchanger be repaired instead of replaced?
No. A cracked heat exchanger cannot be safely welded or patched because it separates the combustion chamber from the household air supply, and any repair attempt would not restore that separation reliably. The furnace has to be replaced.
Why did my water heater get tagged right after my furnace was replaced?
This is a common pattern in Ajax. When a furnace is upgraded to a sidewall-vented condensing model, the water heater left behind in the shared chimney often cannot generate enough heat on its own to establish proper draft, which causes spillage and a tag on the water heater.
Is a cracked heat exchanger covered by a furnace warranty in Ajax?
Some furnace warranties cover the heat exchanger component itself for a set number of years, but labour to remove and replace the unit is usually not covered. Check your original installation paperwork or manufacturer registration for the specific warranty terms on your unit.