How Much Does Furnace Repair Cost in Ottawa? Priced by Fault, With the Diagnostic Fee Nobody Compares

Most furnace repairs in Ottawa are published between $100 and $900, with the diagnostic visit costing $80 to $200 before anyone touches a part. A flame sensor runs $100 to $200 and an igniter $150 to $300. A cracked heat exchanger is $1,500 to $2,500 or more, which is the one repair that turns into a replacement conversation.

Those figures come from Gas Man Ottawa, published 2026-03-25 and last modified 2026-04-02, read 2026-08-28. The second list on this page is WeatherFix, published 2026-03-03 and last modified 2026-08-24, also read 2026-08-28. Two Ottawa companies, quoted for figures they publish themselves. This directory publishes no prices of its own and neither company is listed on it.

Furnace repair priced by fault, with the symptom beside it

This is the more useful of the two lists, because it prices the fault rather than the visit. The middle column is the symptom Gas Man Ottawa publishes beside each price, so you can work backwards from what your furnace is doing to the band you are probably in before the technician arrives.

Two details from the same page change what a quote means. A flame sensor cleaning is priced at $100 to $150 and a replacement at $150 to $200, so the cheapest thing on the list is a cleaning job. And a blower motor splits by type: $400 to $600 for a basic PSC motor against $700 to $1,200 for the variable-speed ECM motor found in high-efficiency furnaces. If a quote says blower motor and nothing else, that is an $800 question left open.

Gas Man Ottawa also makes the point that decides most bills: the same symptom can be two different repairs. A furnace that will not ignite is, in its own example, either a $150 igniter or an $800 gas valve. The diagnosis is what separates them, and the diagnosis has its own price.

The diagnostic fee is the number nobody compares

Both companies publish one and they nearly agree. Gas Man Ottawa puts it at $80 to $200. WeatherFix puts it at $99 to $150, described as what you pay just to have the technician come out and diagnose the problem. At the top of that band the diagnostic costs as much as the most expensive fault in the cheapest half of the table, which is why it belongs in the comparison rather than in the small print.

The part that moves real money is whether it comes off the repair. WeatherFix publishes the only guidance either company gives: some companies waive the diagnostic fee if you proceed with the repair, this is less common with major repairs, and it should always be clarified on the phone. There is no rule to look up. Ask before you book, and ask for a number rather than an assurance.

Two Ottawa companies charge the emergency premium in two different places

The two lists look flatly incompatible here, and it is because they measure the premium in different places. Gas Man Ottawa says emergency service, meaning after hours, weekends and holidays, typically costs $50 to $150 more than regular-hours service. WeatherFix prices the after-hours visit itself at $250 to $400 or more, and adds that the fee alone can be $250 to $350 before any repair work begins.

Read against WeatherFix's own standard diagnostic of $99 to $150, its after-hours call-out is about $150 to $200 dearer, against Gas Man's premium of $50 to $150. The two bands touch at $150 rather than contradicting each other. What differs is the sentence you are quoted: one adds a premium to the bill, the other replaces the price of the call-out. Between a $50 premium and a $350 call-out fee sits the whole disagreement, so ask which one you are being told.

In Ontario the person repairing your furnace needs a certificate, and the company needs a registration

Gas work is governed by O. Reg. 212/01, made under the Technical Standards and Safety Act, 2000, and administered by TSSA rather than by Skilled Trades Ontario. Section 6 (1) names the verbs that matter here: no person shall install, alter, purge, activate, repair, service or remove any appliance, equipment or other thing employed in the handling or use of gas unless that person holds a certificate for the purpose. Section 5 adds that nobody may handle gas without a licence. Section numbers read from the regulation by this directory on 2026-08-12.

TSSA issues those certificates as G.1, G.2 and G.3 grades, and the company is regulated separately from the person: section 21 (1) states that no person shall act as a contractor unless registered for the purpose. A registered company can send an uncertificated person, and a certificated person can work for an unregistered company, so the two questions are not one question.

One exemption is worth knowing because it describes a normal service call. Section 6 (3) permits someone without the certificate to do the work in the presence of a certificate holder, which is what makes an apprentice on your basement floor entirely legitimate. Someone uncertificated working alone on your furnace is a different situation.

Repair or replace: one published rule, and what it does not tell you

WeatherFix publishes what it calls the $5,000 Rule: multiply the age of the unit by the repair quote, and if the total exceeds $5,000, seriously consider replacing. Its own worked example is a heat pump 12 years old with a $600 repair, so 12 times $600 is $7,200 and the answer is replace. Gas Man Ottawa publishes no threshold at all, and puts a new furnace installation in Ottawa at $3,500 to $7,500.

Run the arithmetic on the table above and the rule bites early. A 15-year-old furnace hits $5,000 at a repair of about $333, which is most of the middle of that table. That is one company's rule of thumb rather than a standard, it is silent on whether the unit is safe, and a cracked heat exchanger is a safety question before it is a money one. Use it to decide whether to get a replacement quote, not to decide instead of getting one.

A permit note, since the question comes up the moment replacement does. The City of Ottawa's list of projects not requiring building permits names "Installation of air conditioning units or heat pumps" and "Replacing an existing hot water tank", read 2026-08-28. It does not name a furnace in either direction, so this page does not tell you what the answer is. The City asks anyone unsure of their scope to contact its Building Code Client Service Centre or call 3-1-1, and that is the call to make. Our furnace and air conditioner cost guide carries the replacement side in full, including three install price lists and the cooling-side licence that is a different regulator again.

What to ask before the technician leaves

• The TSSA contractor registration number, and the certificate grade of the person on site. Two different things from section 21 (1) and section 6 (1), and a firm can be right on one and wrong on the other.
• Whether the diagnostic fee comes off the repair. Worth $80 to $200 and settled in one sentence on the phone before anyone drives over.
• Which part, by name, and which type. Blower motor is not an answer when the published spread inside that phrase is $400 to $1,200.
• The warranty on the part and the warranty on the labour. Neither Ottawa list publishes these, so they are a question rather than a lookup.

Gas Man Ottawa prices annual maintenance at $100 to $200, which is inside the band of a single diagnostic visit. That is the cheapest line on either list, and the only one you get to schedule rather than have scheduled for you by a cold morning.