Questions to ask before replacing a boiler
Replacing a boiler is a significant investment that should last 15 years or more, so the questions you ask before the work begins shape how well it performs and how much it costs you over time. The right questions also help you tell a thorough contractor from a rushed one.
Whether your boiler heats radiators, in-floor loops, or supplies your hot water, the goal is a correctly sized, efficient, safely installed unit with clear warranty coverage. HeatLand Heating & Cooling has guided Metro Vancouver and Fraser Valley homeowners through boiler decisions since 1999. Here are the questions worth asking before you sign anything, and why each one matters.
Questions About Sizing and System Type
Start with fit. Ask how the contractor determined the boiler size and whether they performed a heat-loss consideration rather than simply matching the old unit’s output. Oversized boilers short-cycle and waste fuel; undersized ones can’t keep up in cold weather. Ask whether a combi boiler (heat plus on-demand hot water in one unit) or a system boiler with a separate tank suits your household’s hot water demand and existing setup. If you have radiators or in-floor heating, ask how the new boiler matches those loops and whether outdoor reset controls are recommended for efficiency. Also ask whether your existing gas line can supply the new appliance or needs upsizing. These questions reveal whether the contractor is designing for your home or just swapping a box, which makes a real difference in comfort and running costs.
Questions About Efficiency, Venting, and Rebates
Ask about the efficiency rating of the proposed boiler and what it means for your energy bills, especially if you’re moving from an older mid-efficiency unit to a high-efficiency condensing model. Clarify the venting: condensing boilers use sealed plastic venting and a condensate drain, so ask what venting changes your installation requires. Ask whether any current rebate programs apply to the equipment you’re considering. Rebate details and amounts change and are set by the program, so ask the contractor to point you to current official program information rather than quoting a figure that may be outdated. Also ask about the condensate drain routing and any freeze-protection considerations for the venting. Understanding efficiency and venting up front helps you compare quotes fairly rather than on price alone.
Questions About Warranty, Cost, and the Installer
Protect your investment by clarifying the warranty. Ask what the manufacturer warranty covers, how long, and whether registration is required (many warranties require professional installation and registration). Ask about any labour warranty on the installation itself. On cost, request a detailed written quote that itemizes equipment, labour, permitting, venting, and any additional components rather than a single lump sum, and confirm what could change the price. Ask whether financing is available if that helps you choose a better unit. Crucially, confirm the installer is licensed, insured, and TSBC-certified for gas work, and that a permit and inspection are included. HeatLand provides written quotes, handles permitting, offers financing, and installs with certified gas fitters. A contractor who answers these clearly is one you can trust with a 15-year investment.
Safety Note: Verify Licensing Before Anyone Touches Gas
The single most important safety question is whether the person installing your boiler is a licensed, TSBC-certified gas fitter. Gas work performed by unqualified installers can result in leaks, carbon monoxide risk, failed inspections, and voided insurance. Never accept an off-the-books cash job that skips permits to save money, because you inherit all the risk. Ask to confirm licensing and that a permit will be pulled. After installation, ensure CO detectors are in place. If you ever smell gas or suspect CO, leave and call for help immediately. Choosing a licensed contractor like HeatLand from the start is the best safeguard for your family and home.
Quick Checklist
- How was the boiler sized (heat-loss, not just old output)?
- Combi or system boiler, and why for my home?
- What venting and gas line changes are required?
- Is a permit and inspection included?
- What does the warranty cover and is registration needed?
- Is the installer licensed, insured, and TSBC-certified?
| Question Area | What to Ask | Why It Matters |
|---|---|---|
| Sizing | How was size determined? | Comfort and efficiency |
| Efficiency | What is the rating? | Energy bill impact |
| Venting/gas | What changes are needed? | Safety and code |
| Warranty | Coverage and registration? | Long-term protection |
| Installer | Licensed and TSBC-certified? | Safe, legal install |
Frequently Asked Questions
What is the most important question to ask a boiler contractor?
Whether they are licensed, insured, and TSBC-certified for gas, and whether a permit is included. This underpins safety, legality, insurance validity, and warranty. Sizing and warranty questions matter too, but confirming qualified, permitted installation protects you most, since improper gas work can be dangerous and costly to remedy.
Should I just match my old boiler’s size?
Not automatically. Homes change with insulation upgrades, additions, or window replacements, and the old unit may have been oversized. A proper heat-loss consideration ensures the new boiler is correctly matched, which improves comfort and efficiency and reduces short-cycling. Ask the contractor how they determined the size rather than assuming a like-for-like match.
How do I compare boiler quotes fairly?
Ask each contractor for an itemized written quote covering equipment, labour, permitting, venting, and any extra components. Compare efficiency ratings, warranty terms, and what’s included rather than just the bottom-line price. A cheaper quote that omits permits, venting, or proper sizing can cost more in the long run. Clarity makes comparison meaningful.
Are there rebates for a new boiler in BC?
Rebate programs and amounts change over time and are set by the program provider, so exact figures require current official confirmation. Ask your contractor which programs may apply to your chosen equipment and to point you to the official program details. Avoid relying on a specific rebate figure quoted casually, since it may be outdated.
Reviewed by the HeatLand Heating & Cooling team — licensed HVAC contractor serving Metro Vancouver & the Fraser Valley since 1999. This article is for general guidance only. If you smell gas, suspect a carbon monoxide leak, or are unsure about any electrical or gas component, stop troubleshooting immediately and call a licensed technician or 911.