Furnace and Air Conditioner Repair in London, Ontario: Lake-Effect Winters and Humid Summers

What fails in winter

High-efficiency furnaces vent through plastic pipes on an outside wall, and lake-effect snow drifts over them or the exhaust ices at the outlet; the furnace shuts down on a pressure-switch fault and restarts once the pipes are cleared. Condensate lines through unheated spaces freeze and lock the furnace out. Beyond that, the winter failures are ignitors and flame sensors that were marginal in October, blower motors that seize under continuous running, and cracked heat exchangers on furnaces past fifteen years. Note the flashing code on the control board before you call.

Older London homes with mid-efficiency furnaces from the 1990s and 2000s have a different set of failures, and parts are getting scarce; a technician who quotes a control board for one of those should also quote a replacement.

What fails in summer

London’s humid summers keep air conditioners cycling for months, and the first hot week of the year exposes the weak ones: a failed capacitor that leaves the outdoor fan silent, low refrigerant from a slow leak that ices the indoor coil, a condensate drain blocked with algae that floods the furnace cabinet. An oversized air conditioner, common in subdivisions where the builder picked one size, cools the house fast without removing humidity, which is why it feels cool and clammy at once.

Refrigerant work must be done by a technician with refrigerant handling certification, and a good one finds the leak before recharging. Recharging without a leak repair is a short-term fix.

Who may do the work in Ontario

Gas appliances fall under the Technical Standards and Safety Authority: the technician on the gas side of your furnace must hold a TSSA gas technician certificate, and a replacement is registered and inspected. Electrical work on the furnace or condenser circuit belongs to a licensed electrical contractor under the Electrical Safety Authority, with a notification of work filed. If you smell gas, leave the house before calling, then phone Enbridge Gas’s 24-hour emergency line, printed on every bill, or 911 from outside.

Ontario’s fire code requires carbon monoxide alarms in homes with fuel-burning appliances; test yours when you change the furnace filter. Tenants without heat in the heating season should report it to the landlord in writing and then to the City under its property standards by-law.

• Furnace and AC make, model and age
• Flashing code and symptom pattern
• Filter condition
• Outdoor unit fan turning and lines free of ice
• Rebate paperwork if replacement is on the table

Repair, replace, or a heat pump for both

Get the diagnosis first. A capacitor, igniter, flame sensor or blower motor on equipment under fifteen years old is normally worth repairing; a cracked heat exchanger or a failed compressor on old equipment usually is not, because the part costs a large share of a new unit. Ask for both quotes in writing, and ask what rebate programs Enbridge or the federal government currently offer, because those change with each budget.

A cold-climate heat pump handles London’s winters with a gas or electric backup for the coldest weeks and replaces the air conditioner as well, with better dehumidification than an oversized AC. Ask installers for the balance point for your home and make sure the backup is in the quote.