When and how to replace a hot water tank
A hot water tank should be replaced when it leaks, rusts through, no longer keeps up or is well past its expected life. Replacing it before it fails lets you choose the fuel, size and type instead of taking whatever is in stock during a flood.
How do you know the tank needs replacing?
Water pooling at the base is the clearest sign. A leak from the tank itself cannot be repaired, and it can get worse fast. Leaks from fittings and valves are a different matter and a plumber can often fix those.
Other warning signs are rust-coloured hot water, a rumbling or popping noise from sediment, a heater that runs constantly yet struggles to keep up, and age. Many tanks last roughly a decade or somewhat more, and the date is on the rating plate. See heating system lifespans in Canada for the wider picture. If the tank is merely not heating, check water heater not heating first, since a failed element or thermostat is cheaper than a new tank.
Which type of replacement should you choose?
The simplest swap is a like-for-like tank on the same fuel. Other options deserve a look while the old unit is out.
- Standard tank, gas or electric. Lowest upfront price, with standby heat loss. A high-efficiency gas tank can use a sealed vent and cost more to install.
- Tankless. No standby loss, more to install. See tank versus tankless.
- Heat pump water heater. Uses less electricity, needs space and air. See heat pump water heaters in Canada.
- Solar preheat. Adds a solar tank ahead of the heater, with higher capital cost. See solar hot water cost in Canada.
Size by peak-hour use, not by habit. The new tank does not need to match the old one, and hot water tank sizing explains how to check.
What does the replacement job involve?
A licensed plumber or gas fitter shuts off the water and fuel, drains and disconnects the old tank, sets the new one in place and reconnects water, venting or electrical supply, and the temperature and pressure relief valve. Gas work needs a gas-qualified tradesperson. Many municipalities and provinces require a permit or inspection for water heater work, and the installer usually knows the local rules. The local authority or provincial safety regulator can confirm.
The job often takes a few hours when nothing complicates it. Venting changes, a new gas line, a drain for condensate or a move to a different fuel add time and cost. Ask the installer to haul away the old tank, and keep the paperwork for the warranty.
What affects the price, and what about rentals?
The quote reflects the tank type and capacity, the fuel, venting and electrical changes, the accessibility of the space, the permit and the region. Prices vary by region and year, so quotes decide. Get at least two written quotes that name the model, the warranty on tank and parts, and whether removal and permit are included. Our advice on reading a furnace quote applies to water heater quotes as well.
In some areas water heaters are rented from a supplier. If yours is, read the contract for the monthly charge, the term and any buyout or removal terms before replacing it, and compare the total with buying outright. Rebates for efficient water heaters change often, so check the Government of Canada energy-efficiency pages, the provincial energy ministry and your utility.
Quick answers
How long does a hot water tank last?
Many last roughly a decade or a little more, depending on water quality, maintenance and the model. The rating plate shows the manufacture date.
Can a leaking hot water tank be repaired?
A leak from the tank body cannot be repaired and means replacement. A leak from a valve or fitting may be fixable by a plumber.
Do I need a permit to replace a water heater?
Often yes, especially for gas units. Your installer or local authority can tell you what applies where you live.