Water heater replacement

Most Ottawa households replace a water heater twice in the time they own a house, and most do it in a hurry on the day the old one leaks. Spending twenty minutes on it in advance is worth several hundred dollars and a considerably better appliance.

Step one: find out whether you own it. A large share of Ottawa water heaters are rented, and a rental agreement usually means the rental company must be called and may charge to remove their equipment, and sometimes an exit or buyout fee applies. Check your gas or hydro bill for a monthly rental line before you call anyone. Buying out an old rental tank and replacing it with an owned unit is very often the cheapest long-run option, because rental payments continue indefinitely on equipment that is long depreciated.

Step two: choose the type. A conventional gas tank is cheapest to install, holds 150 to 250 litres (40 to 60 gallons) and then has to recover. A tankless gas unit heats on demand and never runs out, but needs a larger gas line and a sealed vent. An electric tank is cheap to install and expensive to run. A heat pump water heater is two to three times as efficient as an electric tank, with a caveat below.

Step three: the venting and the gas. This is where a swap becomes a project. An older atmospherically vented gas tank sharing a masonry chimney with a furnace cannot be replaced with a power-vented or tankless unit without new venting, and taking the tank off a shared chimney can leave the furnace improperly vented. A tankless unit typically needs an upsized gas line. All of that belongs in the quote rather than in a discovery on installation day.

Step four: the installation. Water off, tank drained, old unit out, new unit set and levelled, supply and vent connections made, the relief discharge routed properly, then fill, purge and commission. A drain pan with a routed discharge is cheap and worth insisting on over finished space. Electrical work on an electric or heat pump unit must be reported to the Electrical Safety Authority before it begins, by a Licensed Electrical Contractor if you are hiring (Electrical Safety Authority, Notifications and inspections).

How long it takes. A like-for-like gas or electric tank swap is two to four hours. A tank converted to tankless is a full day, sometimes two if the gas line has to be run. A heat pump water heater is three to six hours including the condensate route and any electrical work.

What it costs in Ottawa in 2026. Indicative. A conventional gas tank supplied and installed, $1,800 to $3,200. An electric tank, $1,500 to $2,600. A power-vented gas tank, $2,500 to $4,200. A tankless gas unit including venting, $4,500 to $8,000, more if the gas line needs upsizing. A heat pump water heater, $4,000 to $7,000 including electrical work. Venting changes, a new gas run, or a chimney liner where a furnace is left orphaned are each separate and can add $1,000 to $3,000.

Running costs, from a source you can check. Under the Regulated Price Plan prices effective 1 November 2025, Ontario time-of-use electricity is 9.8 cents per kilowatt hour off-peak, 15.7 mid-peak and 20.3 on-peak, the tiered option is 12.0 cents for the first block and 14.2 above it, and the ultra-low overnight plan prices overnight electricity at 3.9 cents with on-peak at 39.1 (Ontario Energy Board, Electricity rates). That last plan is genuinely relevant here, because a well-insulated tank on a timer can do most of its heating overnight at 3.9 cents. A heat pump water heater on the ultra-low overnight plan is about as cheap as domestic hot water gets in Ontario. Natural gas pricing is set separately and changes quarterly, so compare against your own gas bill rather than a generic figure.

What makes an Ottawa basement different, and the heat pump caveat. A heat pump water heater works by taking heat out of the air around it and putting it into the water. In a Barrhaven basement that is a real benefit in July, when it dehumidifies and cools a space that wants both. In January it is taking heat out of a space your furnace is paying to heat, which claws back part of the efficiency gain. It also needs air volume, generally a reasonably open basement rather than a sealed mechanical closet, and a condensate drain. It is still usually the right answer in a finished Ottawa basement of decent size, and it is the wrong answer in a small closed utility room.

Which credential to ask for, and the permit question. Plumber is a compulsory trade in Ontario under code 306A, checkable on the Skilled Trades Ontario public register (Skilled Trades Ontario, Plumber, trade code 306A). Gas work is separately licensed in Ontario and a gas technician certification is required to work on gas appliances and piping, so ask specifically who is doing the gas connection and under what certification. Electrical work for hire needs a Licensed Electrical Contractor (Electrical Safety Authority, Notifications and inspections). On permits, the City of Ottawa's exemption covers replacing existing fixtures, and alterations, additions or extensions to a plumbing system need a permit (City of Ottawa, Do I need a building permit), so a straight swap generally does not and a conversion that reworks piping and venting may. Ask.

What to ask before you buy. Is my current unit rented, and what does exiting cost. Which type for this basement, and why. Is my venting suitable, and if not what does the change cost. Will the furnace be left orphaned on the chimney. Does the gas line need upsizing, and who does the gas work under what certification. Is a drain pan included. What is warranted on the tank, the parts and the labour.