Last Updated on June 4, 2026 by Anta Plumbing Master Plumber
Tankless water heater installation costs $3,500 to $6,500 for most homes in 2026, and complex jobs reach $8,500. The final price turns on your gas line, venting, and electrical setup.
Hot water that never runs out sounds simple, yet the installation rarely is. Older homes across the region were built for storage tanks, so their gas lines and venting often fall short of what an on-demand unit demands. That gap is exactly where surprise charges hide. Read on to see every cost in plain numbers, plus how to keep yours down.
How Much Does a Tankless Water Heater Cost in the GTA?
A tankless water heater costs $3,500 to $6,500 installed for most GTA homes. That price covers the unit, professional labour, and basic permits. The total climbs, though, when your home needs a new gas line, upgraded venting, or panel work. In those cases, it can reach $8,500 or more
The spread is wide because your final price depends on your house, not just the heater. A straight swap in a newer home stays low. Many older Toronto and Etobicoke homes cost more, since their gas lines were sized for a small tank.
A tankless unit needs more fuel, so the line, venting, or panel often needs an upgrade first. To estimate your own job before booking, use the plumbing cost calculator.
Tankless Water Heater Cost by Unit Size
Tankless units are sized by flow rate, measured in gallons per minute (GPM). The wrong size leaves you short of hot water during peak use.
| Unit type | Flow rate | Unit price | Installed cost | Best for |
| Point-of-use | 1 to 6 GPM | $150 to $500 | $500 to $1,300 | One fixture, like a garage sink |
| Whole-house | 7 to 11+ GPM | $600 to $2,600 | Varies by home | A full GTA household |
Household size drives the choice. A couple, for instance, needs 5 to 7 GPM. A family of four needs 7 to 9 GPM. And a big home with three bathrooms needs 9 to 11+ GPM.
A GTA factor changes the math here. In winter, our groundwater drops near 35 to 40°F. The unit must heat it by roughly 80°F. As a result, a tankless heater delivers less GPM here than in warmer regions. So Toronto and Oakville homeowners should size up, not down.
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Major Factors Affecting the Tankless Water Heater Cost
Energy Type and Fuel Type
The fuel you choose shapes both the price and the install. Here is how the four types compare on installed cost in the GTA.
| Fuel type | Installed cost | Best suited for |
| Natural gas | $3,000 to $5,500 | Most GTA homes with gas service |
| Electric | $2,700 to $6,000 | Condos and homes without gas |
| Propane | $2,000 to $3,800 | Rural GTA without gas lines |
| Solar | Rarely used here | Not practical in our climate |
Electric Tankless Water Heaters
Electric units cost $1,800 to $3,000 on the unit side. They install simply, too, because they need no venting. A whole-house electric model often needs an electrical panel upgrade, though, which pushes the total to $2,700 to $6,000.
For that reason, electric works best for condos and homes without a gas line. In a tower, the rules differ again, since high-rise plumbing follows its own access and pressure demands.
Natural Gas Tankless Water Heaters
Natural gas is the most common pick across the GTA. Installed cost runs $3,000 to $5,500. These units deliver higher flow rates, so they suit family homes with existing gas service from Enbridge. If you’re switching from electric or oil, though, expect a new gas line connection before the unit goes in.
Propane Tankless Water Heaters
Propane costs $2,000 to $3,800 installed. It performs much like natural gas, but it needs a propane tank on your property. As such, it only fits rural pockets of the GTA without natural gas lines.
Solar Tankless Water Heaters
Solar exists, yet almost no GTA homes use it for hot water. The upfront cost is high, and the winter sun is weak. For those reasons, gas or electric makes far more sense here.
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Quantity, Quality, and Brand
Running several showers at once usually calls for one high-GPM unit. For a distant bathroom, some homes add a point-of-use heater alongside it, which adds cost.
Quality counts just as much. A premium condensing unit costs more upfront, yet it lasts longer and runs cheaper. Budget units fail sooner in our hard-water region.
On brand, plumbers across Canada most often recommend Navien and Rinnai.
| Brand | Unit price | Standout feature |
| Navien (NPE-S2) | $1,200 to $2,300 | 98% efficiency, built-in recirculation |
| Rinnai (V, RU) | $850 to $1,500 | Strong flow rates, proven in Canada |
| Noritz (EZ111) | $1,300 to $2,100 | Up to 11.1 GPM, 25-year warranty |
Price alone should not drive the decision. Choose the brand and model that match your home’s hot water demand.
Gallon per Minute (GPM)
GPM is the figure that decides your unit size. It measures how much hot water flows each minute. A higher GPM costs more but covers more fixtures at once.
Match it to your habits. A shower and a dishwasher together draw roughly 4 to 5 GPM. Add laundry, and the demand climbs fast. A dripping tap inflates these numbers, so book a faucet repair before you size the unit.
Remember the winter factor too: cold inlet water cuts real output, so a 9 GPM unit may deliver only 5 GPM in January. Size for peak winter demand, not the summer rating.
Condensing vs. Non-Condensing
This choice affects both your unit price and your venting cost.
- Condensing units cost $200 to $400 more upfront. They run 10 to 15% more efficiently. They vent through a cheap PVC pipe. But they need a condensate drain.
- Non-condensing units cost less to buy. They need pricier stainless-steel venting. Efficiency sits a bit lower.
For most GTA homes, condensing is the smarter buy. The fuel savings and cheaper PVC venting offset the higher unit price within a few years. Only skip it when the install spot has no nearby drain for the condensate.
Materials, Labour Costs, and Permits
Three core costs sit inside every quote.
| Cost item | Typical range | What it covers |
| Materials | A few hundred dollars | Vent pipe, gas fittings, valves, condensate line |
| Labour | $1,000 to $3,000 | 3 to 5 hours for a swap; a full day for a conversion |
| Permits | $150 to $500 | Gas and water heater approval, plus inspection |
Labour scales with complexity (Eccotemp). A simple same-spot swap stays low, whereas a full tank-to-tankless conversion takes most of a day.
Permits apply in both Toronto and Oakville (Anta Plumbing). In Ontario, the TSSA governs gas work while the ESA governs electrical work. A licensed installer pulls these permits and books the inspection, so the paperwork never lands on you.
The same inspection often flags other code items, like backflow prevention testing, which protects your drinking water from cross-contamination.
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Additional Tankless Water Heater Costs
These extras explain why one quote beats another. They’re often invisible until a tech inspects your basement.
| Add-on | Typical cost | When you need it |
| Electrical panel upgrade | $1,000 to $2,500 | Electric units on a full panel |
| Gas line upsizing | $800 to $2,000 | Most tank-to-tankless gas jobs |
| Vent upgrade | $400 to $1,200 | Old metal flue or new route |
| Old unit removal | $75 to $250 | Almost every replacement |
Electrical Updates
Electric tankless units need a dedicated 40 to 60 amp circuit. If your panel is already full, then you’ll need an upgrade first. A 100A to 200A panel upgrade costs $1,000 to $2,500 in Toronto. Even gas units, meanwhile, need a small electrical connection for the controls.
Insulation
Tankless units run hot vent pipes and condensate lines. In tight or finished mechanical rooms, these need proper clearance and pipe insulation. A condensate line on an exterior wall can freeze without it, which is a common cause of frozen pipes in GTA winters. The added labour is modest and protects the system long term.
Gas Line Installation
This is the number one budget-buster across the GTA. Because a tankless unit fires far hotter than a tank, your old gas line is often too small. Upsizing to a 3/4-inch line then costs $800 to $2,000, depending on the run (Premier Plumbing). So if your home has an undersized line, proper gas line sizing keeps the install safe and up to code.
Home Structure Changes
Older Toronto semis rarely have a clean path for new vent pipes. As a result, routing them can mean cutting through finished walls, which raises both labour and material costs. On older properties, too, an aging main line sometimes surfaces during the work; in that case, a water service upgrade gets folded into the same visit.
Vent Types
Gas units must vent combustion gases outside. To do that, power vents and sealed direct vents replace old metal flues. Expect $400 to $1,200 for a vent upgrade. Condensing units help here, since they use cheaper PVC pipe.
Utility Bills
A tankless heater cuts your running costs. It uses 24 to 34% less energy than a tank because it heats water only on demand.
In Ontario, gas tankless units cost less to run than electric ones. That’s because high Toronto Hydro rates make electricity nearly three times pricier to operate. So for most GTA homes with gas service, a gas unit wins on monthly bills.
| Factor | Gas tankless | Electric tankless |
| Monthly run cost | Lower in Ontario | Higher on Hydro rates |
| Lifespan | 18 to 22 years | 18 to 22 years |
| Best fit | Homes with gas service | Condos, no-gas homes |
These units also outlast a tank by years. With proper care, a good tankless runs 18 to 22 years, whereas a standard tank lasts just 10 to 15.
One local point worth knowing. GTA water runs hard, so mineral scale builds inside the heat exchanger fast. Left alone, that scale cuts efficiency and shortens the unit’s life. Annual descaling costs $150 to $300 and keeps the warranty valid. Many homeowners go further and fit a water softener, which slows the buildup and protects the unit for years. For cleaner drinking water on top of that, a reverse osmosis system pairs well with the softener.
DIY vs. Professional Water Heater Installation
Tankless installation is not a legal DIY job in Ontario. Gas work needs a TSSA-certified gas fitter, and electrical work needs an ESA-licensed electrician. The permits themselves require a licensed contractor.
A faulty installation risks carbon monoxide, fire, and water damage. It also voids the warranty and can derail an insurance claim or a future home sale.
Professional installation costs more, but it secures safety, code compliance, and a valid warranty. For a job involving gas and 200 amps, that protection is worth the price.
Tips to Save on Tankless Water Heater Installation Costs
A few smart choices lower the final bill:
- Choose a properly sized unit to avoid overspending on higher-capacity models you don’t need
- Compare multiple licensed installers to get competitive quotes before committing
- Install during a larger plumbing upgrade to reduce labour duplication costs
- Switch from electric to gas only if gas line already exists to avoid expensive new line installation
- Reuse existing venting where code-compliant instead of installing a full new system
- Place the heater near existing plumbing lines to reduce pipe extension work
- Check for local rebates or energy-efficiency incentives that lower upfront costs
- Avoid emergency or rush installation, which often comes with premium labour charges
- Bundle installation with other home efficiency upgrades for package pricing discounts
- Choose a standard model instead of premium smart units if features aren’t necessary
- Ensure your home’s electrical or gas capacity is sufficient to prevent upgrade expenses
Conclusion
Your tankless water heater installation cost comes down to one thing: what your home already has in place. Before you commit, get a written quote that itemizes the gas line, venting, and electrical work. That single step prevents most surprise charges.
Ready for an honest, fixed estimate across Toronto, Oakville, and the GTA? Call Anta Plumbing today.
Frequently Asked Questions
How long does the installation take?
A same-spot swap takes 2 to 4 hours. A first-time tankless install with new gas and venting takes most of a day.
Can I install a tankless water heater myself in Ontario?
No. Gas and electrical work require licensed pros and permits. DIY installs are illegal and unsafe here.
What’s the cheapest tankless option?
A point-of-use electric unit is the cheapest, starting from $500 installed. That said, it only serves one fixture, not a whole home.
Do tankless heaters need a water softener in the GTA?
Our water is hard, so scale builds up fast. A softener and annual descaling protect your unit and warranty.
Is a tankless water heater worth it compared to a tank?
For most family homes, yes. It lasts 18 to 22 years and cuts energy use by up to a third, so the higher upfront cost pays back over time.
Can I replace a 40-gallon tank with a tankless unit?
Yes, though the swap often needs a larger gas line, new venting, or a condensate drain. These upgrades explain why a conversion costs more than a like-for-like tank.
