For most older homes in Unionville, Markham and Richmond Hill, a new storage tank is the simpler swap and usually costs less up front. Tankless makes sense if you keep running out of hot water, want the floor space back, and your gas line, venting and water can support it. If your current heater is rented, read the rental agreement before anything is removed, because its buyout and return terms are part of the decision.
What an older house adds to the decision
Much of Unionville is 1970s and 1980s subdivisions, with heritage homes around Main Street. Older parts of Markham and Richmond Hill are similar. Most of these homes are on their second or third water heater, and the house was not designed with tankless in mind. Three things usually decide what is practical:
- Venting. Older gas tanks often vent into a chimney, sometimes shared with the furnace. If the furnace has already been replaced with a high-efficiency unit, the water heater may now be alone in that chimney, which affects what can safely go there next. Tankless units and power-vented tanks usually vent through a side wall with plastic pipe, so a new opening is needed.
- Gas supply. A gas tankless heater has a much larger burner than a tank. The existing gas line may be too small and need upgrading.
- Electrical. Gas tankless units need an electrical outlet nearby. Whole-house electric tankless heaters need a lot of electrical capacity, which older panels often do not have. That is a question for a licensed electrician.
On Main Street Unionville, which is a heritage conservation district, anything that changes the outside of the house, such as a new vent through a wall, should be checked with the City of Markham first.
Planning work like this? Tell us about it and we will connect you with one independent local contractor. Free, and no obligation.
Tank and tankless, side by side
A storage tank:
- Is usually a simpler like-for-like replacement, often using the existing venting and gas line.
- Stores a set amount of hot water. Big households can run out, and it loses some heat while it sits.
- Comes in standard and power-vented versions. Ask about heat pump models too, if the space suits one.
A tankless heater:
- Heats water as you use it, so it does not run out, but only up to its flow rating. Run several showers and the dishwasher at once and it can fall behind.
- Delivers less hot water in winter, when the water coming into the house is colder.
- Mounts on a wall and frees up floor space, which is useful when finishing a basement.
- Needs regular descaling, and condensing models need a drain for condensate.
- Usually costs more to install, especially when the gas line or venting has to change.
Water hardness varies across Markham and Richmond Hill depending on which supply serves your street. Scale builds up in tanks and tankless heat exchangers alike, so ask the plumber whether regular descaling or a softener makes sense in your house. Gas piping and appliance connections in Ontario must be done by a certified gas technician, so ask the plumber whether they hold that certification or bring in someone who does.
Owned or rented? Check your agreement first
Many Ontario homes rent their water heater rather than own it. A rented unit belongs to the rental company, and your agreement sets out what happens if you replace it early: whether there is a buyout, how the old unit is returned, and when the rental charges stop.
- Look for a rental sticker on the tank, and a rental charge on your gas bill or a separate monthly bill.
- Find your agreement and read the buyout and return terms, or call the rental company and ask.
- Do not let a rented tank be removed and disposed of without arranging its return. Otherwise you may keep paying rent on a tank you no longer have.
- If you are buying an older home, ask whether the heater is rented and get a copy of the agreement.
Checklist: what to find out before you choose
- Your current heater: gas or electric, tank size, and age from the label.
- Owned or rented, and the rental terms if it is rented.
- How it is vented now, and whether it shares a chimney with the furnace.
- How many bathrooms you have, and how many showers or appliances run at once.
- Whether you run out of hot water now, and when.
- Whether you are finishing the basement or need the floor space.
- Whether the home is in a heritage district.
When to call a plumber
Call if your tank is leaking, rusty or rumbling, if you are running out of hot water sooner than you used to, or if you want both options priced before the old one fails. If it is leaking now, shut off the cold-water supply to the heater and set a gas unit to off or pilot. If you smell gas, leave the house and call your gas utility or 911 from outside.
What drives the cost: tank or tankless, any gas line upgrade, venting changes and new wall openings, condensate drainage, electrical work, removal of the old unit, permits, and rental buyout terms if any. Ask the plumber to price both options so you can compare like with like. Our water heater page has more on gas, electric and propane setups.
Frequently asked questions
Is tankless cheaper to run?
It avoids the heat a tank loses while it sits, so many households use less energy. How much depends on how you use hot water, and the savings do not always cover the higher installation cost. Ask for both options priced for your house.
Can a tankless heater go where my old tank was?
Often it can go nearby, but venting, gas supply and a condensate drain decide the final spot. A plumber can tell you on site what would need to change.
How do I know if my water heater is rented?
Look for a rental company's sticker on the tank and a rental charge on your gas bill or a separate bill. If you are not sure, your home purchase documents may include the agreement.
If you are weighing tank against tankless, the short form is free to use and sends your request to one local plumber who covers Unionville, Markham or Richmond Hill.