Electric vs Gas Water Heater: Which Costs Less to Install?
An electric tank costs less upfront than gas, but venting, wiring and running costs can flip the real total — here's how to compare.
A straight swap to an electric hot water tank typically runs $1,950 installed, against $2,500 for a like-for-like gas tank. The electric unit is usually the cheaper purchase and the simpler install — but it isn't automatically the cheaper appliance to own, because gas and electricity come with different hidden costs once you look past the sticker price.
Why electric tanks install for less
An electric tank has no flue, no combustion air requirement and no gas line to connect. If you're doing a same-for-same changeover — old electric tank out, new electric tank in, same wiring — the job is mostly drain, disconnect, lift, reconnect. That's reflected in the lower end of our figures.
A gas tank needs a gas line already in place (or run new, which adds cost fast), plus proper venting to the outside. If your existing flue is shared with an old furnace or needs relining, that adds to the bill before the tank itself is even considered.
| Material | Typical | Usual range | Lifespan |
|---|---|---|---|
| Electric tank, 40-50 gal | $1,950 | $1,500 – $2,500 | 10-15 years |
| Gas tank, 40-50 gal | $2,500 | $1,950 – $3,200 | 8-12 years |
| Tankless gas (condensing) | $4,750 | $3,700 – $6,200 | 15-20 years |
| Heat pump (hybrid) water heater, 50 gal | $5,750 | $4,500 – $7,500 | 12-15 years |
The wiring catch on electric
The quoted electric price above assumes your home already has a dedicated circuit sized for the new tank. If it doesn't — common in older houses with a fuse panel or a circuit shared with something else — budget for $3,150 instead of a simple swap. That covers a new breaker, wiring run from the panel, and the disconnect at the tank. It's the single most common reason an "electric is cheaper" assumption falls apart on site, so get an electrician to actually look at the panel before you commit to electric on price alone. If the panel itself needs attention beyond one new circuit, our House rewiring guide covers what a broader electrical upgrade costs.
The venting catch on gas
Standard gas tanks (around 80% efficient) vent through a metal flue, usually tying into an existing chimney or vent shared with the furnace. If that flue is undersized, corroded, or was sized for an old furnace that's since been replaced with a high-efficiency model, you may need new venting — $3,450 covers a switch that includes a new gas line and venting from scratch. If you're also due to replace the furnace, it's worth having one trade quote both jobs together, since venting work often overlaps; see our Furnace replacement guide for what that side costs.
Running costs: the part the sticker price misses
This is where the comparison usually turns. In most of Canada, a unit of energy from natural gas costs less than the same unit from electricity, so a standard gas tank is usually cheaper to run month to month than a standard electric tank — all else equal. That gap narrows, and in some cases reverses, in provinces with low-cost hydroelectricity, where electric rates are closer to gas on a per-unit basis. It also narrows a lot if you compare against a heat pump water heater rather than a plain electric-resistance tank: a heat pump unit uses a fraction of the electricity of a standard electric tank for the same hot water, at a higher purchase price. If efficiency matters more to you than the lowest install cost, a heat pump water heater or a tankless gas unit are worth pricing against both tanks before you decide — ask your contractor for all three quotes at once.
What actually drives the final number
Beyond the tank type, three things move the price on any water heater job:
- Size — a larger household needs a bigger tank or a higher-output tankless unit, which costs more.
- Access — a tank in a tight closet or crawlspace takes longer to swap than one in an open basement or garage.
- Code work triggered by the swap — an inspector who flags your existing gas line, flue, or electrical disconnect as non-compliant will add work you didn't originally ask for.
None of that shows up until someone looks at the actual installation, which is why two quotes for "the same job" can land far apart. For the full range across tank types, see Water heater replacement.
Our take
If your existing fuel source, gas or electric, is already run to the right spot with the right capacity, stick with it: a same-for-same swap is the cheapest water heater job there is in either fuel. The maths only gets interesting when you're choosing a fuel from scratch, or when the existing wiring or venting needs work anyway — at that point, price out electric-tank, gas-tank, tankless-gas and heat-pump options side by side rather than assuming the lower sticker price wins. And once you have a written quote in hand, run it past our "is my quote fair" tool before you sign, so you know whether the number reflects your actual house or just a generic average.