Questions to Ask an HVAC Contractor Before You Sign

Before signing with an HVAC contractor, ask for their gas fitter or refrigeration licence number, proof of insurance, whether they'll perform a load calculation before quoting equipment size, what warranty terms apply to parts versus labour, and for two references from installs completed in the last year. A contractor who answers all five without hesitation has cleared the basic vetting bar; one who deflects any of them is a reason to keep shopping.

The short answer

Five questions do most of the vetting work: licence number, insurance proof, whether a load calculation will be done, warranty terms in writing, and recent references. A contractor who answers all five directly, without deflecting, has cleared the basic bar. Treat hesitation on any one of them as information.

The questions, organized by category

Licensing and legitimacy

• What’s your TSSA gas technician licence number (or refrigeration mechanic certification for heat pump work)? A legitimate contractor provides this without hesitation.
• Can I see proof of liability insurance? Ask to see a certificate directly, not just be told coverage exists.
• How long have you been operating under this business name? A business that recently rebranded after complaints under a previous name is a pattern worth knowing about.

Process and technical competence

• Will you do a load calculation before quoting equipment size, or are you sizing based on the old unit / square footage alone? Sizing based only on the old unit repeats any original sizing mistake.
• What efficiency tier are you quoting, and why is it right for my home? The answer should reference your usage, insulation, or budget — not default to whatever’s easiest to install.
• If this is a heat pump install, is the unit cold-climate rated, and what’s its output at -15°C or -25°C? Standard heat pumps and cold-climate heat pumps perform very differently in a Canadian winter; the contractor should know the spec without looking it up on the spot.
• What’s the installation timeline, and how many jobs are you running that same week? A contractor spread too thin is more likely to rush your install.

Pricing and paperwork

• Can you itemize equipment, labour, permits, and disposal separately? See our full quote checklist for what a fair breakdown looks like.
• What are the parts and labour warranty terms, in writing? These come from different sources (manufacturer vs. contractor) and are the term most often left vague verbally.
• What’s the deposit structure, and what happens if I need to cancel? A partial deposit is normal; full payment upfront is not.
• Are you a registered installer for any rebate programs I might be eligible for? Relevant if you’re pursuing a heat pump rebate that requires a registered contractor.

References

• Can you give me two references from jobs completed in the last 12 months? Recent references matter more than old ones — ask specifically about install quality and whether the crew showed up on schedule.

Red flags during the sales process

• Pressure to sign the same day, especially tied to a “today-only” discount
• Reluctance or delay in providing a licence number
• A quote with no written breakdown (see our quote checklist for what should be itemized)
• Vague or verbal-only warranty promises
• Full payment demanded before work begins

How to use this list

You don’t need to interrogate every contractor with all eleven questions in one sitting — most come out naturally over a quote conversation. What matters is noticing when one goes unanswered or gets deflected. That’s the signal, more than any single answer on its own.