Water Heaters & Rentals · Tankless
Tankless vs Traditional Tank: Which One Fits Your Home?
Endless hot water and a 20-year lifespan on one side; simplicity and a lower price on the other. Here's the honest comparison — including the maintenance cost tankless ads leave out.
How do the two actually compare?
| Tankless | Traditional tank | |
|---|---|---|
| Hot water | Heats on demand — the shower doesn't run cold because the laundry ran | A stored supply (typically 40–60 gallons); run it out and you wait for recovery |
| Lifespan | Roughly 20 years | Roughly 8–12 years |
| Energy use | Only heats when water flows — no standby losses keeping a tank hot all day | Keeps the full tank hot 24/7, reheating as it cools |
| Space | Wall-mounted, about the size of a suitcase — frees the floor space | A full floor footprint in the utility room |
| Maintenance | Annual descaling in most cases — see below | An occasional flush and anode rod check; far less routine attention |
| Installed cost | Higher — typically in the $4,000–$6,500 range depending on fuel, venting and gas line work | Lower — typically in the $2,000–$3,500 range installed |
Cost figures are typical Ontario ranges, not quotes — fuel type, venting and where the unit has to go move the real number. An exact quote comes from a look at your home.
What's the maintenance truth about tankless?
Most tankless units need annual descaling — a flush that removes the mineral build-up hard water leaves in the heat exchanger. Skip it and efficiency drops, error codes appear, and warranties can be questioned. If a service company does it for you, budget roughly $250–$350 a year. Some newer units are built to resist scale far better, but the honest default assumption is: tankless trades the tank's big replacement bill for a smaller annual service habit. Homeowners on well water or with very hard municipal water should take that line seriously — a water softener ahead of the tankless unit reduces the scaling significantly (see water treatment).
Who is tankless actually for?
Homes that run out of hot water — bigger households, back-to-back showers, a soaker tub that empties the tank. Homes tight on space. And homeowners who plan to stay put long enough for the 20-year lifespan to pay back the higher install price. It's also the natural landing spot for renters escaping a rental contract who never want a tank payment again.
Who should just keep a tank?
Smaller households that never run out of hot water — a tankless unit solves a problem you don't have. Homes where the install would need major gas line or venting work that balloons the price. And anyone who knows they won't keep up with annual descaling and has hard water: a neglected tankless is a worse ownership experience than a simple, reliable tank. There's no wrong answer here — there's a right answer per house.
Tankless — common questions
Can a tankless unit really never run out?
It can't run out of stored water because there isn't any — it heats as you use it. What it does have is a flow limit: run more taps at once than the unit is sized for and the water temperature can dip. Sizing for your household's peak demand is the whole game, which is why the questionnaire asks about bathrooms and household size.
Does tankless work with well water?
Yes, with the descaling conversation turned up — well water often carries more minerals. A softener or scale protection ahead of the unit, plus staying on the annual flush, keeps it a good experience.
I'm renting my tank now. Is tankless a way out?
It's one of the two landing spots after an exit — own a tank, or go tankless. Exit first (buyout math on the rental exit page), then choose the replacement with the full picture in front of you.
Is tankless right for your house?
Four questions — current heater, household size, bathrooms, fuel — and you'll get an honest fit assessment, not a sales pitch.
Take the Tankless Check