# Tankless Water Heater Installation Toronto | From $3,500 > Need tankless water heater installation in Toronto? Navien, Rinnai & Bosch units from $3,500 installed, sized for winter. Call 647-254-4113. URL: https://besthvactoronto.ca/tankless-water-heater-installation/ ![Best HVAC Toronto technician installing a wall-mounted condensing tankless water heater in a Toronto basement](/images/hero/technician-in-plain-grey-uniform-installing-a-wall.webp) # Tankless Water Heater Installation in Toronto & the GTA Last updated: October 26, 2026 Best HVAC Toronto [/ →](/) has over 20+ years of Greater Toronto Area experience specialising in tankless water heater installation across Toronto and the wider GTA. Condensing tankless on-demand water heater installation, replacement, and repair across Toronto and the GTA. Our TSSA-certified crew installs Navien, Rinnai, and Bosch tankless units sized to household DHW flow rate demand (typically 12-16 LPM at Toronto winter temperature rise), with power direct vent (PDV) or concentric venting configured to code, condensate drainage tie-in, and gas line upsize where required to handle the higher BTU demand versus a conventional tank. Every install includes UEF (Uniform Energy Factor) verification for ENERGY STAR rebate eligibility, condensing heat exchanger commissioning at rated output, and annual descaling flush service enrollment to protect the heat exchanger from Toronto moderately hard water. We handle rental tank buyouts through Reliance and Enercare and coordinate the swap so hot water service is uninterrupted. Condensing tankless installations run $3,500-$6,500 installed depending on capacity, venting complexity, and gas line requirements. Water heater repair diagnostics start from $150; typical descaling flush service runs $180-$250 annually and is included in maintenance plan enrolments. Pricing depends on flow rate, venting route, and whether gas or water piping needs upsizing. Same-day weekday capacity. 24/7 dispatch for gas emergencies and Enbridge Red Tags. - check\_circle TSSA G1/G2 certified - check\_circle 20+ years experience - check\_circle Manufacturer-Authorized Dealer call Call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) View pricing [#pricing →](#pricing) payments **From $3,500**. installed - star star star star star 4.9 (150+ reviews) - verified TSSA G1/G2 Certified & $2M Insured - bolt 2-Hour Emergency Response - workspace\_premium Manufacturer-Authorized Dealer Common problems ## Sound familiar? hot\_tub ### Running out of hot water with a full house Tankless units heat on demand, so a large household doesn't run out mid-shower. square\_foot ### Want to reclaim the space a tank takes up Tankless installation frees up floor space in the mechanical room, a common ask in smaller Toronto homes. build ### Not sure if tankless is worth the higher upfront cost We walk through when tankless wins on efficiency versus when a high-efficiency tank is the better value for your household. ## How does an on-demand water heater work? Best HVAC Toronto installs, replaces, and repairs condensing tankless water heaters in residential homes across Toronto and the GTA, from North York detached houses to semi-detached homes in East York and newer townhouses in Mississauga. Every install is completed by TSSA-certified G1 and G2 gas technicians to Ontario Building Code and TSSA gas code, and carries a 2-year labour warranty. A conventional tank [/tank-water-heater-installation/ →](/tank-water-heater-installation/) keeps 150 to 250 litres of water hot around the clock whether you use it or not. A tankless unit heats water only when a tap opens, firing a condensing heat exchanger and raising the water temperature as it flows through. Nothing is stored, so nothing sits losing heat, and you cannot run out of hot water part way through the third shower of the morning. The trade-off is that a tankless unit is limited by flow rate rather than by volume. Capacity is expressed as gallons per minute at a given temperature rise, and that is where most disappointing installations go wrong. A unit rated at 6 GPM is quoted at a temperature rise measured under mild conditions. Toronto’s municipal water is drawn from Lake Ontario and arrives considerably colder in February than in August, so the same unit might only manage 4 GPM at the same output temperature in the middle of winter. We size on the winter figure, counting fixtures and realistic simultaneous use, because that is the condition your household will judge it by. ![Technician measuring hot water flow rate and temperature at a kitchen tap after commissioning a tankless water heater](/images/content/technician-measuring-hot-water-flow-rate-and-tempe.webp) The other pre-install check that matters is gas supply. A tank water heater might draw 40,000 BTU. A tankless unit firing flat out draws 150,000 to 199,000. Half-inch supply piping that was perfectly adequate for the tank frequently is not adequate for the tankless, and undersized gas supply produces poor performance and nuisance error codes. We calculate the load against your Enbridge meter and quote any required gas line upsizing [/gas-line-installation-bbq-hookups/ →](/gas-line-installation-bbq-hookups/) up front. Going tankless also changes the rest of the mechanical room. If an old atmospheric tank shared a chimney with a mid-efficiency furnace or boiler, removing it can leave that appliance alone in an oversized flue, which then needs a liner or new venting. The Best HVAC Toronto crew checks the furnace, boiler [/boiler-installation-repair/ →](/boiler-installation-repair/) , and any hydronic air handler before quoting, so the new water heater and the existing heating system work together. ### What every water heater installation includes Household flow-rate sizing, gas load calculation, removal and disposal of the old tank where applicable, wall-mounted condensing unit, isolation valve kit for future descaling, new concentric or power direct venting, condensate drainage and neutralisation, gas piping modifications where required, full commissioning with gas pressure verified under load, and manufacturer parts coverage registered on your behalf. We install Navien, Rinnai, Bosch, and Rheem condensing units. For water heater repair on an existing tankless, common faults are ignition failures, flame sensor and flow sensor errors, scale-related overheating codes, and condensate blockages. Diagnostics start from $150 and you get a written repair quote before any parts are replaced. ## Is going tankless worth it for your household? ### Tankless usually wins when You regularly run out of hot water, you have three or more bathrooms, you want the mechanical room floor space back, you are already replacing venting or gas piping for other reasons, or you plan to stay in the home long enough to recover the higher install cost through lower standby losses. ### A high-efficiency tank is often better when Demand is modest and predictable, the mechanical room already accommodates a tank comfortably, the gas supply would need substantial upsizing, or you are selling within a few years. We are happy to quote both and let you compare. ### Maintenance is not optional Annual descaling is what separates a tankless unit that lasts 20 years from one that fails in 10. Mineral scale builds inside the heat exchanger, restricting flow and eventually triggering fault codes. Because we fit isolation valves on every installation, the annual flush is a quick, inexpensive visit rather than a job requiring pipework. ## How much does tankless water heater installation cost in Toronto? Installed pricing runs $3,500 to $6,500 (2026 pricing). Flow-rate capacity comes first: a higher GPM unit for a larger household costs more than an entry model. Second is what you are replacing. Swapping an existing tankless for a new one is the cheapest path since venting and gas supply are usually already correct. Converting from a tank means new venting, condensate management, and often gas upsizing. Third is the venting route. A unit that can terminate through a nearby exterior wall is straightforward; one needing a long run through a finished basement in an Etobicoke bungalow or a tight mechanical closet in a Scarborough townhouse costs more. Fourth is gas piping, which is the single most common reason a tank-to-tankless conversion costs more than people expect. Fifth is optional extras such as a recirculation loop for near-instant hot water at distant fixtures. Every one of these is assessed during the free on-site estimate and itemised in a written quote before we begin. Financing is available on approved credit. ## Sizing for flow rate: GPM, temperature rise, and UEF A tankless water heater heats water on demand as it flows through the unit, rather than heating and storing a fixed volume in a tank. When a hot tap opens somewhere in the home, the flow sensor detects incoming cold water, the gas valve opens, and the burner fires. Cold water passes through the primary heat exchanger where it absorbs heat from the combustion, and hot water flows out to the tap within seconds. When the tap closes, the burner shuts off. No standing storage, no standby heat loss, no waiting for a tank to reheat. The critical spec on any tankless is DHW flow rate, expressed in litres per minute (LPM) or gallons per minute (GPM) at a specific temperature rise. Every ENERGY STAR tankless carries a UEF rating too, which measures thermal efficiency and standby losses across a standardised draw pattern. Toronto’s cold water enters at roughly 5-7°C in winter, and typical hot water setpoint is 49°C, giving a required temperature rise of about 42-44°C. A residential condensing tankless like a Navien NPE-240A2 delivers about 13 LPM at that rise, enough for two showers simultaneously plus a hand basin. Larger homes with three-plus bathrooms and multiple simultaneous hot water demands may need a higher-capacity unit like the NPE-320A2 or a cascaded pair of smaller units. Undersizing shows up as cold-showering when someone starts a second tap while another is already running. We size against actual hot water demand at your home, not against a generic square-footage recommendation. ## Endless hot water: the benefits and the trade-offs Benefits are straightforward. Endless hot water: as long as the burner fires, hot water flows. Space savings: the unit is roughly the size of a large suitcase and wall-mounts, freeing up the floor area a 40-60 gallon tank would occupy. Energy savings: elimination of standby losses (a tank loses heat 24/7 to keep its contents warm even when no one is home) typically saves 20-30% on domestic hot water energy use. Longer lifespan: quality tankless units run 15-20 years compared to 10-12 for tanks. Higher rebate eligibility: ENERGY STAR condensing tankless units are more likely than standard tanks to qualify for Ontario efficiency incentives, and we confirm current eligibility for your chosen model before you commit. Drawbacks are real too. Upfront cost is meaningfully higher than a tank ($3,500-$6,500 installed for a tankless versus $1,800-$4,500 for a tank), especially if the install includes venting, gas line upsize, or electrical work. Flow rate is capped by the unit’s BTU output, so simultaneous heavy use (three showers running plus a load of dishes) can exceed capacity in a mid-tier unit. Annual descaling flush is required in Toronto’s moderately hard water; skipping it shortens lifespan and voids some warranties. Winter cold water inlet temperature reduces flow rate compared to summer, so a unit sized for summer may struggle in January. And short-cycle draws (someone runs 3 seconds of hot water to wash their hands) waste some energy on the ignition-to-flow lag. On balance, tankless wins for most homes replacing an aging tank in 2026, especially with rebate stacking and the space savings, but it is not universally correct. ## Tank vs tankless: which fits a Toronto home? The decision usually comes down to household size, hot water usage pattern, upfront budget, and available install space. Tank water heaters ($1,800-$4,500 installed, 10-12 year lifespan) work well for smaller households (one to three people) with moderate simultaneous demand, older homes where space and existing venting favour a tank swap, and budget-focused installs where the higher upfront cost of tankless is not worth the operating savings within your expected time in the home. A properly-sized 50-gallon high-efficiency gas tank meets the daily needs of most Toronto detached homes at reasonable cost. Tankless water heaters ($3,500-$6,500 installed, 15-20 year lifespan) win for larger households (four-plus people) with high simultaneous hot water demand, homes replacing an existing rental tank where the buyout cost is being folded into the upgrade, and any owner planning to stay in the home 10+ years to recover the upfront cost through lower operating expenses. Where a qualifying model attracts Ontario efficiency incentives, the net upfront gap to a tank swap narrows further. Hybrid heat pump water heaters (a third category) sit between the two on cost and win on operating efficiency in unfinished basements with adequate ambient temperature. Best HVAC Toronto models all three during the estimate against your Enbridge bill history and hot water pattern. If you are searching for tankless installation near you, our crews cover Toronto, North York, Scarborough, Etobicoke, Mississauga, Vaughan, Markham, and the rest of the GTA, Monday through Saturday from 7 AM to 8 PM. Transparent pricing ## How much does tankless cost in Toronto? Pricing depends on flow rate, venting route, and whether gas or water piping needs upsizing. receipt\_long Written quote before any work begins. No hidden fees. ### Straight swap Replacing an existing tankless Starting from $ 3,500 installed - check Like-for-like condensing unit - check Reuses existing venting where suitable - check Isolation valves for future descaling - check Manufacturer registration filed on your behalf Get a quote [tel:+16472544113 →](tel:+16472544113) MOST COMMON ### Tank to tankless conversion Most common project Starting from $ 5,000 installed - check GPM flow-rate sizing - check New concentric venting - check Gas supply upsized if required - check Old tank removed and disposed Get a quote [tel:+16472544113 →](tel:+16472544113) ### High-demand household Larger homes, multiple bathrooms Starting from $ 6,500 installed - check Higher GPM condensing unit - check Recirculation option available - check Full gas load review - check Commissioning and flow testing Get a quote [tel:+16472544113 →](tel:+16472544113) Prices are guide ranges for Toronto and the GTA. Final pricing depends on your equipment, access, and site conditions, and we confirm it in writing before starting. Request a free estimate [/contact/ →](/contact/) or call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) . savings Financing available on approved credit, plus lease-to-own with zero down on qualifying installs. Why us ## Why choose Best HVAC Toronto for tankless? severe\_cold ### Sized on winter inlet temperature Tankless capacity is quoted at a temperature rise. Toronto's winter inlet water is cold, so a unit sized on summer figures will disappoint in January. We size for February. propane\_tank ### Gas supply checked first A tankless unit can draw three to five times the gas of a tank when firing. We verify the supply carries it rather than installing and hoping. plumbing ### Isolation valves fitted as standard Annual descaling is what keeps a tankless unit alive. We fit the isolation valve kit on every install so servicing is straightforward and inexpensive. handshake ### Honest about whether it suits you Tankless is excellent for some households and a poor fit for others. We will tell you when a high-efficiency tank is the better buy. ## How Best HVAC Toronto compares | Feature | Typical provider | Best HVAC Toronto | | --- | --- | --- | | Sizing basis | Nominal GPM rating | GPM at Toronto winter inlet temperature | | Gas supply check | Assumed adequate | Load calculated and verified | | Isolation valves | Optional extra | Fitted as standard | | Old tank removal | Charged separately | Included in the quote | | Warranty handling | Homeowner registers the equipment | Manufacturer registration filed by us | How it works ## How does our tankless service work? 1. 1calculate ### Size the demand We count fixtures, estimate simultaneous use, and check winter inlet water temperature to establish the flow rate in GPM your household actually needs. 2. 2search ### Check gas and venting Tankless units draw far more gas than a tank when firing. We verify supply capacity and plan the venting route before quoting. 3. 3build ### Install Wall-mounted unit, isolation valve kit, new venting, condensate management, and removal of the old tank, usually completed in a single day. 4. 4verified ### Commission and hand over We verify gas pressure under load, check the temperature rise at the taps, set the output temperature, and show you how the isolation valves work. ## Not sure what your tankless situation needs? Get a straight answer and a written price, with the numbers to back it up. No pressure, no scare tactics. call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) Book Online [/contact/ →](/contact/) Our work ## Recent tankless projects Click any image to enlarge. Reviews ## What customers say about our tankless work starstarstarstarstar4.9 out of 5 from 150+ customer reviews star star star star star > Clear quote, no upselling, and they were realistic about which unit actually made sense for our house rather than pushing the biggest one. PPeter G.Erin Mills, Mississauga star star star star star > Fast, clean installation and they were careful about the neighbours during the work. Good communication throughout. MMarisol T.Pape Village, East York star star star star star > Tight utility space and they still found a unit that fit properly with correct clearances. No shortcuts taken. CColin B.Leaside, East York FAQ ## Tankless questions, answered ### How much does tankless water heater installation cost in Toronto? expand\_more Installed pricing runs $3,500 to $6,500 in 2026, with financing available on approved credit. Replacing an existing tankless with a similar unit sits at the lower end. Converting from a tank costs more because it usually needs new venting, condensate drainage, and often an upsized gas line. Larger homes needing higher flow rates or a recirculation loop sit at the top of the range. ### Is a tankless water heater actually worth it? expand\_more For households of four or more people, or homes with three or more bathrooms, usually yes. Tankless makes sense if you frequently run out of hot water, want the floor space back, or plan to stay in the home long enough to recover the higher install cost through lower standby losses. It makes less sense for a small household with modest, predictable demand, where a high-efficiency tank is often the better value. We will tell you which case you are in. ### Will I really get endless hot water? expand\_more Endless, yes, but not unlimited flow. A tankless unit heats water continuously so it never runs out, but it can only raise a certain volume per minute by a certain number of degrees. If the unit is sized for 5 GPM and you run two showers plus a dishwasher, the temperature will drop. Correct sizing on your actual simultaneous demand is what prevents that. ### Why does winter matter for tankless sizing? expand\_more Capacity is quoted as flow rate at a given temperature rise. Toronto's incoming water is roughly 15 degrees warmer in August than in February, so a unit that comfortably delivers 6 GPM in summer might manage only 4 GPM in winter for the same output temperature. We size on the winter figure, which is the only one that matters when it is cold. ### Does a tankless unit need a bigger gas line? expand\_more Frequently, yes. A tank water heater might draw 40,000 BTU while a tankless unit fires at 150,000 to 199,000 BTU when running flat out. Existing half-inch supply piping is often inadequate. We calculate the load and quote any upsizing before starting, since discovering it mid-install is the classic cause of a job going over budget elsewhere. ### What is descaling and how often is it needed? expand\_more Descaling flushes a mild acid solution through the heat exchanger to dissolve mineral scale, which otherwise restricts flow and eventually causes error codes and failure. Annually is the standard recommendation for the GTA's water. Because we fit isolation valves on every install, the flush is quick and inexpensive, and it substantially extends the unit's life. ### How long does a tankless water heater last? expand\_more Typically 15 to 20 years or more with annual descaling, compared with 10 to 12 years for a conventional tank. Neglected units scale up and fail much sooner, often within 10 years. Most manufacturers make warranty coverage conditional on documented annual maintenance, which is another reason we fit the isolation valves as standard. ### What is UEF and how do I compare units? expand\_more UEF, or Uniform Energy Factor, is the current efficiency measure for water heaters, replacing the older EF rating. It accounts for standby loss, cycling, and recovery efficiency. Condensing tankless units typically reach 0.93 or higher, compared with roughly 0.60 to 0.70 for a conventional atmospheric tank, which is where the running-cost saving comes from. ### How is a tankless unit vented? expand\_more Condensing tankless units vent through sealed PVC or polypropylene, usually as a concentric vent that draws combustion air and exhausts flue gases through a single wall penetration, or as a power direct vent with separate pipes. They cannot use an existing chimney. Venting route and termination clearances are assessed during the site visit. ### Can I add a recirculation loop for instant hot water? expand\_more Yes. A recirculation loop keeps hot water near the fixtures so there is little wait at the tap, which matters in larger homes with long pipe runs. It can be run on a timer or on demand via a button or motion sensor. It adds cost and a small standby energy penalty, so we discuss whether the convenience justifies it for your layout. ### Am I allowed to install my own tankless water heater in Ontario? expand\_more Not if it runs on gas. In Ontario, connecting a gas-fired water heater, including the gas piping and venting, must be done by a TSSA-certified gas technician working for a TSSA-registered contractor, and the venting must meet CSA B149.1. A DIY gas connection can also void the manufacturer warranty and cause problems with your home insurance. Best HVAC Toronto's G1 and G2 technicians handle the gas, venting, and commissioning, backed by a 2-year labour warranty. ### Can I buy a tankless unit from Home Depot and have it installed? expand\_more Big-box stores like Home Depot sell tankless water heaters, but store models are often chosen on the box's nominal GPM rather than on Toronto's winter inlet temperature, and they still need a licensed gas technician to connect them. Our installed price includes a Navien, Rinnai, Bosch, or Rheem condensing unit sized for February, the gas load check, venting, isolation valves, old tank removal, and manufacturer registration filed on your behalf. ### Do you repair tankless water heaters as well as install them? expand\_more Yes. We diagnose and repair ignition failures, flame and flow sensor faults, scale-related error codes, and condensate blockages on residential tankless units across Toronto and the GTA. Diagnostics start from $150, and you receive a written quote before any parts are replaced. ## Related services water\_heaterTank Water Heater Installation & RepairGas, electric, and hybrid tank water heaters installed, plus help exiting rental contracts. [/tank-water-heater-installation/ →](/tank-water-heater-installation/) device\_thermostatBoiler Installation & RepairCombi, condensing, and hydronic boiler installation, repair, and annual maintenance. [/boiler-installation-repair/ →](/boiler-installation-repair/) propane\_tankGas Line Installation & BBQ HookupsCertified gas line runs for BBQs, outdoor kitchens, fireplaces, generators, and appliances. [/gas-line-installation-bbq-hookups/ →](/gas-line-installation-bbq-hookups/) ![](/images/hero/hvac-technician-in-plain-grey-uniform-kneeling-bes.webp) 24/7 for gas emergencies, red tags, no-heat and no-AC ## Ready to book tankless? Condensing tankless on-demand water heater installation, replacement, and repair across Toronto and the GTA. Our TSSA-certified crew installs Navien, Rinnai, and Bosch tankless units sized to household DHW flow rate demand (typically 12-16 LPM at Toronto winter temperature rise), with power direct vent (PDV) or concentric venting configured to code, condensate drainage tie-in, and gas line upsize where required to handle the higher BTU demand versus a conventional tank. Every install includes UEF (Uniform Energy Factor) verification for ENERGY STAR rebate eligibility, condensing heat exchanger commissioning at rated output, and annual descaling flush service enrollment to protect the heat exchanger from Toronto moderately hard water. We handle rental tank buyouts through Reliance and Enercare and coordinate the swap so hot water service is uninterrupted. Condensing tankless installations run $3,500-$6,500 installed depending on capacity, venting complexity, and gas line requirements. Water heater repair diagnostics start from $150; typical descaling flush service runs $180-$250 annually and is included in maintenance plan enrolments. Written quotes before work begins, and manufacturer parts coverage registered on your behalf. call Call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) Get a Free Estimate [/contact/ →](/contact/) - check\_circle Manufacturer registration filed on your behalf - check\_circle Written quotes before work starts - check\_circle TSSA G1/G2 certified, WSIB covered Cities we serve ## Tankless Water Heater Installation Across the GTA On-demand tankless water heater installation with power direct venting, DHW flow-rate sizing, and annual descaling flush service across the GTA. ### Tankless Water Heater Installation in North York City of Toronto [Tankless Water Heater Installation in North York →](/tankless-water-heater-installation/north-york/) ### Tankless Water Heater Installation in Etobicoke City of Toronto [Tankless Water Heater Installation in Etobicoke →](/tankless-water-heater-installation/etobicoke/) ### Tankless Water Heater Installation in Scarborough City of Toronto [Tankless Water Heater Installation in Scarborough →](/tankless-water-heater-installation/scarborough/) ### Tankless Water Heater Installation in Vaughan City of Vaughan [Tankless Water Heater Installation in Vaughan →](/tankless-water-heater-installation/vaughan/) ### Tankless Water Heater Installation in Markham City of Markham [Tankless Water Heater Installation in Markham →](/tankless-water-heater-installation/markham/) ### Tankless Water Heater Installation in Mississauga Peel Region [Tankless Water Heater Installation in Mississauga →](/tankless-water-heater-installation/mississauga/) ### Tankless Water Heater Installation in Brampton Peel Region [Tankless Water Heater Installation in Brampton →](/tankless-water-heater-installation/brampton/) ### Tankless Water Heater Installation in Richmond Hill City of Richmond Hill [Tankless Water Heater Installation in Richmond Hill →](/tankless-water-heater-installation/richmond-hill/) ### Tankless Water Heater Installation in East York City of Toronto [Tankless Water Heater Installation in East York →](/tankless-water-heater-installation/east-york/) ### Tankless Water Heater Installation in Oakville Halton Region [Tankless Water Heater Installation in Oakville →](/tankless-water-heater-installation/oakville/) ### Tankless Water Heater Installation in Burlington Halton Region [Tankless Water Heater Installation in Burlington →](/tankless-water-heater-installation/burlington/) ### Tankless Water Heater Installation in Ajax Town of Ajax [Tankless Water Heater Installation in Ajax →](/tankless-water-heater-installation/ajax/)