# Tankless Water Heater Installation Toronto | Best HVAC > Condensing tankless water heater installation and repair in Toronto. Endless hot water, GPM flow sizing, venting, and descaling. Free estimates, transparent pricing. URL: https://besthvactoronto.ca/tankless-water-heater-installation/ ![Technician installing a wall-mounted condensing tankless water heater in a Toronto basement](/images/hero/technician-in-plain-grey-uniform-installing-a-wall.webp) # On-Demand Tankless Water Heater Installation in Toronto Last updated: September 4, 2026 Condensing tankless water heater installation, replacement, and repair for endless on-demand hot water. - check\_circle TSSA G1/G2 certified - check\_circle 20+ years experience - check\_circle 2-Year Labour Warranty 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 2-Year Labour Warranty 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 a tankless water heater work? 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 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 and quote any required gas line upsizing [/gas-line-installation-bbq-hookups/ →](/gas-line-installation-bbq-hookups/) up front. ### What is included in every tankless installation 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 a 2-year labour warranty alongside manufacturer coverage. ## Is tankless the right choice for your home? ### 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. ## What affects tankless installation cost in Toronto? 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 finished space 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 estimate and itemised in a written quote before we begin. 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 2-year labour warranty 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 | | Labour warranty | 1 year | 2 years | 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. 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 It depends on your household. 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 20 years or more with annual descaling, roughly double the life of 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. ## 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 water heater installation, replacement, and repair for endless on-demand hot water. Written quotes before work begins, and a 2-year labour warranty. call Call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) Get a Free Estimate [/contact/ →](/contact/) - check\_circle 2-year labour warranty - check\_circle Written quotes before work starts - check\_circle TSSA G1/G2 certified, WSIB covered