Tankless vs. Tank Water Heater: Costs and Which Is Right for Your Ontario Home (2026)
Written by the Northland Home Comfort team — TSSA-registered heating, cooling and hydronics contractor (FS-R-50021) serving Simcoe County and Muskoka. Updated October 2026.
Short answer: In Ontario in 2026 a gas or propane tank water heater costs about $2,200 to $4,200 installed; a condensing tankless unit costs $4,500 to $7,500 installed, more if the gas line has to be upsized. Tankless units last 20 years or more against 10 to 13 for a tank, use 20 to 30 percent less fuel, and never run out of hot water. A tank is still the right choice for small households, tight budgets and homes where the gas supply or venting makes tankless impractical. Either way, owning beats renting within a few years.
Cost comparison (installed, Ontario 2026)
| Tank (gas/propane) | Tankless (condensing) | |
|---|---|---|
| Installed cost | $2,200 – $3,200 atmospheric; $3,000 – $4,200 power-vent | $4,500 – $7,500 |
| Electric option | $1,800 – $2,800 | Not practical for whole homes on residential service |
| Lifespan | 10 – 13 years | 20+ years with annual descaling |
| Efficiency | 60 – 67% (standard), 80%+ (condensing tank) | 94 – 98% |
| Hot water supply | 40 or 50 gal, then recovery time | Continuous at the rated flow (typically 2 showers at once) |
| Space | Floor, ~24 in diameter | Wall-hung, size of a carry-on bag |
| Extra install items | Vent liner or power vent if chimney is lost | Gas line upsizing, sidewall venting, condensate neutralizer |
What tankless actually needs
A tankless unit fires at 150,000 to 199,000 BTU, three to four times a tank. Three things follow:
- Gas supply. The line from the meter or propane regulator often has to be upsized. This is the most common hidden cost and the reason some “tankless is cheap” quotes fall apart on install day. We check it on the site visit.
- Venting. Condensing units vent through PVC to the sidewall and need a condensate drain with a neutralizer.
- Sizing by flow and temperature rise. Ontario groundwater arrives at 4 to 8°C in winter. A unit that gives 8 gallons a minute in a brochure (tested with warmer water) gives 4 to 5 here. We size for January, not the brochure.
When a tank is the better choice
- One or two people, modest hot water use.
- Budget replacement after a leak, same day.
- Gas supply or venting that would cost thousands to change.
- A hydronic home: an indirect tank off the boiler is efficient and nearly maintenance-free.
When tankless is the better choice
- Families, large tubs, back-to-back showers.
- Cottages and small mechanical rooms where floor space matters.
- Propane homes, where the fuel savings add up faster.
- Apartment buildings and multi-unit properties: unit-by-unit replacements that cut gas bills and free up space. See our tankless water heater page.
Owning vs renting
Rental tanks in Ontario commonly cost $25 to $50 a month and more as they age; over ten years that is $3,000 to $6,000 for a tank you never own, plus a buyout fee if you want out. Buying a tank pays for itself in three to five years. We handle buyouts and removals as part of the swap. See our water heater page.
Maintenance
Tanks: drain a few litres annually, replace the anode rod around year five. Tankless: annual descaling flush, especially on well water. Skipping the flush is the main reason tankless units fail early around here.
Frequently asked questions
$4,500 to $7,500 for a condensing gas or propane unit, including venting and condensate. Add $500 to $1,500 if the gas line needs upsizing.
For households of three or more, propane homes, and anyone tired of running out of hot water, yes: it lasts about twice as long as a tank and uses 20 to 30 percent less fuel. For one or two people on a tight budget, a good tank is still the sensible choice.
Incoming water is much colder in January, so the unit can heat less of it per minute. Units sized from brochure numbers are undersized for Ontario winters. Proper sizing uses the local groundwater temperature.
Yes. Most condensing tankless units are available in propane versions. The propane regulator and line have to be sized for the unit’s input.
A tank replacement takes two to four hours. A tankless conversion takes most of a day because of venting and gas-line work.
Need a water heater replaced, or want to know if tankless makes sense for your house? Call 705-321-9456 or request a quote. Tank swaps are usually same or next day.
