Signs you need gas water heater replacement
Gas tank heaters age in recognisable ways. Rusty water from the hot side only, a rumble or crackle as the burner fires, water pooling under the tank, or hot water that runs out far sooner than it used to are the common signs. Corrosion at the base of the tank, as opposed to a dripping fitting, generally means the tank itself has reached the end.
The data plate on the side gives the manufacture date, often coded in the serial number. A tank well into its second decade with any of those signs is usually a candidate for replacement rather than repair. If the problem is a pilot or thermocouple on a younger tank, a different heater type is not the first answer; a repair may be.
How we approach it in Markham houses
Many Markham basements have a gas water heater beside the furnace, venting through a shared chimney liner or, on newer homes, a power-vent through the rim joist. Before quoting we look at the venting, the gas supply, the space around the tank and the condition of the shut-off valves. Those details decide what can go back in.
Gas work in Ontario must be carried out by a TSSA-registered contractor with appropriately certified technicians. That applies to anyone you hire, so it is reasonable to ask for those details on every quote.
Rented or owned?
A good share of Markham homes have a rental tank. If yours is rented, the replacement conversation includes the rental company and your contract. Our guide on renting versus buying a water heater walks through what to read before deciding.
The visit, in order
- 1
Shut off the gas or breaker and the cold supply, then drain the tank.
- 2
Check anode, dip tube, thermocouple or elements depending on the fault.
- 3
Install the new part or unit, bleed the air and refill before firing.
- 4
Test the relief valve, draft at the vent hood and outlet temperature at a tap.
Swapping tired gas tanks for new units
- Close the gas cock and the cold supply, empty the old cylinder and unhook it.
- Inspect the venting and correct any slope or clearance problems.
- Set the new tank on a level base, with a drain pan where the location calls for one.
- Connect water lines with new valves and an expansion tank where required.
- Reconnect gas, leak-test every joint, light the unit and check draft.
- Haul the old tank away and walk you through the controls.
Before you call
- Photograph the data plate and the vent connection.
- Check whether a rental sticker is on the tank.
- Clear about a metre around the heater for safe access.
We replace tanks across Markham, including the larger lots around Buttonville. A leaking tank sometimes overlaps with a failing sump pump in the same corner of the basement, so we check both when they share space.
Questions homeowners ask
Markham note: village-core houses tend to hide cast iron and galvanized behind plaster, while Cornell and Box Grove builds run PEX to a manifold. We ask the year your house was built so the right fittings ride along on the truck.
Straight from the phone log
How long does a gas water heater last?
Service life varies with water quality, maintenance and usage. Many tanks run a decade or a little longer; regular flushing and an intact anode help them reach the upper end.
Can I replace a rented tank with one I own?
Generally yes, but the rental contract governs removal and any buyout. Read it, or call the rental company, before arranging the swap.
Do I need an expansion tank?
Where the home has a check valve or pressure-reducing valve creating a closed system, an expansion tank protects the heater and fittings. We check during the visit.
Ready to get it fixed?
One call, a clear explanation, and work finished tidily before we leave.