Price of the unit vs the price installed
This is the single biggest source of confusion when people shop tankless, and it is worth settling before any other number makes sense. The figure on a retail listing is the price of the appliance on its own. The figure that lands on your invoice is the installed price, and for tankless the gap between the two is much wider than it is for a tank.
A tankless unit needs considerably more gas input than the tank it replaces, so the existing gas line is frequently undersized and has to be upsized back toward the meter. It is sealed-combustion, so it needs its own vent run out through an exterior wall with the required clearances rather than reusing a chimney. It needs a condensate drain. On an electric model it needs substantial dedicated circuit capacity. None of that is optional, and none of it appears on the box.
So when you see a low unit price advertised, read it as the starting point rather than the answer. The installed range below is what Ontario homeowners actually pay once the gas, venting and condensate work is included.
A tankless water heater installation in Ontario costs $2,800 to $5,500 fully installed in 2026. The biggest cost drivers are the brand and size of the unit, whether your gas line and venting need upgrades, and how complex the mounting location is. Conventional gas tankless units have no active 2026 rebate (the $1,000 Enbridge program closed Dec 31 2025).
Quick price reference: tankless water heater install in Ontario 2026
| Scenario | Installed price (2026) |
|---|---|
| Direct swap (existing tankless to new tankless) | $2,800 to $3,600 |
| Tank-to-tankless conversion (simple) | $3,400 to $4,400 |
| Tank-to-tankless (needs gas line upgrade) | $4,200 to $5,500 |
| High-output condensing (199K BTU) | $3,800 to $5,200 |
| Outdoor tankless install | $3,200 to $4,200 |
Prices include unit, venting, isolation valves, electrical, gas line modifications up to 2 metres, installation by licensed gas technicians, and labour. Permit fees average $180 in most GTA municipalities and are included in our flat-rate quote.
Cost by brand: Rinnai vs Navien vs Noritz vs Rheem
Four brands cover roughly 85 percent of Ontario tankless installs. We service all four daily across the GTA. Pricing is similar within each performance tier, so brand choice usually comes down to local parts availability, warranty terms, and technician familiarity.
| Brand | Mid-tier model (installed) | High-output condensing (installed) | Notable warranty |
|---|---|---|---|
| Rinnai | RX180iN: $3,200 to $4,000 | RX199iN: $4,000 to $5,200 | 15 yr heat exchanger, 5 yr parts, 1 yr labour |
| Navien | NPE-180S2: $3,000 to $3,800 | NPE-240S2: $3,900 to $5,000 | 15 yr heat exchanger, 5 yr parts |
| Noritz | NRC66DV: $3,200 to $4,000 | NRC1111: $4,100 to $5,300 | 12 to 15 yr heat exchanger depending on model, 5 yr parts |
| Rheem | RTGH-84DVLN: $2,900 to $3,700 | RTGH-95DVLN (199,900 BTU): $3,800 to $4,800 | 12 to 15 yr heat exchanger depending on model, 5 yr parts |
What drives tankless install cost up or down
- Gas line size. Tankless units typically need a 3/4 inch gas line. Many older Ontario homes have a 1/2 inch line feeding the existing tank. Upgrading runs $400 to $900 depending on the run length and access.
- Venting. Condensing tankless units use 2 inch or 3 inch PVC venting. Direct-vent through an exterior wall is cheapest. Vertical roof venting or extended horizontal runs add $250 to $600.
- Electrical. Tankless requires a 120V dedicated outlet within 6 feet of the unit. Adding a new outlet runs $200 to $400.
- Location. Wall-mounting in an existing utility room is easiest. Garage installs need freeze protection ($150 to $300 add-on). Crawl space installs add labour time.
- Water hardness. Peel Region water in Mississauga and Brampton runs about 7 to 7.6 grains per gallon (moderately hard). Adding a water softener at install time saves significant tankless maintenance cost over the unit lifetime. Combined install adds $1,800 to $2,800.
- Recirculation. Built-in recirculation pumps (Navien NPE-A2, Rinnai RUR series) deliver instant hot water at remote fixtures. Adds $400 to $800 to the install but eliminates the 10 to 20 second wait at distant taps.
Tank vs tankless: the 12-year cost math
Tankless costs more upfront but lasts about twice as long and uses 25 to 35 percent less gas. For a typical Mississauga family of four, the 12-year total cost of ownership lands like this:
| Cost line | 50-gallon gas tank | Mid-tier tankless |
|---|---|---|
| Installed cost (before rebate) | $1,600 to $2,400 | $3,400 to $4,400 |
| Eligible rebate | None | None (Enbridge HER+ tankless rebate ended Dec 31 2025; current HRS only funds heat pump water heaters at $500, with an assessment and one other upgrade) |
| Net installed | $1,600 to $2,400 | $2,400 to $3,400 |
| Annual gas cost | $320 to $440 | $220 to $310 |
| Expected lifespan | 8 to 12 years | 15 to 20 years |
| 12-year energy cost | $3,840 to $5,280 | $2,640 to $3,720 |
| Replacement during 12 years? | Likely 1 replacement | None |
| 12-year all-in | $5,440 to $7,680 + 1 replacement | $5,040 to $7,120 |
The math gets significantly better for tankless if your household uses lots of hot water (4+ people, multiple bathrooms, frequent simultaneous showers), or if you stay in the home 10+ years. It gets worse if your household uses little hot water (2 people, single bathroom) or if you plan to move in under 5 years.
The legacy $1,000 Enbridge HER+ rebate (closed Dec 31 2025) and what replaces it
Enbridge gas customers in Ontario used to be able to receive up to $1,000 toward a high-efficiency condensing tankless water heater through the Enbridge HER+ program. HER+ accepted its final applications on December 31, 2025, and there is no active rebate for tankless water heaters in 2026. Budget for a tankless install at full price.
The only active water-heating rebate is $500 through the Home Renovation Savings Program for a heat pump water heater, and it requires a home energy assessment and at least one other upgrade. HRS pays the homeowner by cheque within 60 days after the post-installation application is approved. If a heat pump water heater suits your home, EcoFrost can walk you through that path; we do not process or hold any rebate funds.
Real Mississauga case: Erin Mills tank-to-tankless conversion (April 2026)
A 2,100 sq ft Erin Mills home with 4 occupants replaced their 14-year-old 50-gallon John Wood tank with a Rinnai RX180iN tankless. The existing 1/2 inch gas line needed an upgrade to 3/4 inch (8 ft run, $580). Direct PVC vent through the basement wall avoided any vertical venting cost.
- Equipment + standard install: $3,400
- Gas line upgrade: $580
- Recirculation pump add-on: $620
- Permit (where required): $180
- Total installed: $4,780
- Rebate: none (Enbridge HER+ closed Dec 31 2025; no active 2026 tankless rebate)
- Net cost to homeowner: $4,780
- Year-1 gas savings vs old tank: $185
Homeowner feedback after 30 days: zero cold-water surprises, faster hot water arrival at the master ensuite due to the recirc pump, and the basement reclaimed roughly 8 sq ft of floor space.
When tankless is the wrong choice
- Vacation cottage or rental property with intermittent use. A tank stores hot water; tankless on standby still uses minor power but the higher install cost rarely pays back on low-usage properties.
- Single-bathroom condo with one occupant. Demand is too low to justify the upgrade. A high-efficiency tank or even a heat pump water heater makes more sense.
- Plan to move within 2 years. The 12-year payback math depends on staying in the home long enough to capture the gas savings.
- Home with a working 5 to 7 year old tank water heater. Replacement is rarely cost-justified until the existing tank shows real signs of end of life (leaks, rust, repeated repairs).
Comparing options? Our water heater installation and repair page covers tank, tankless and hybrid units.
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