Quick answer
On a rented water heater or furnace, the rental company pays to repair or replace the unit when it fails from normal use, and you must book through its service line. You pay for what sits outside the unit: venting, gas line or plumbing changes needed to meet current code, damage from misuse or water quality, and any upgrade in size or type.
Who pays for repairs on a rented water heater or furnace? The company that owns it does, for failures of the unit itself, provided you call its service number and not an outside technician. That is what the monthly fee buys. The bills that surprise people come from everything attached to the unit, which the rental agreement treats as your house and not their equipment.
What the rental company repairs at no charge
Standard rental terms in Ontario cover repair or replacement for normal failure: a leaking tank, a dead gas valve or thermocouple, a failed burner or power-vent motor, an igniter or control board on a rented furnace. Parts and labour are included and a covered fault carries no service-call fee. You book through the number on the sticker on the unit, and the company sends its own or a contracted technician.
Not sure whether the equipment is rented at all? The sticker and your bills answer it, and how to tell if a water heater is rented or owned shows where to look.
What the homeowner is still billed for
- Code upgrades at replacement. A swapped tank has to meet today's code, not the code from the year the old one went in. A new vent, a chimney liner, a drain pan or a gas line change is usually charged to you.
- Plumbing and gas piping beyond the unit: shut-off valves, leaking supply lines, a blocked floor drain.
- Damage the agreement puts down to water quality or neglect. Hard water in Halton and Hamilton scales tankless heat exchangers, and a rented tankless that has never been descaled can be treated as a maintenance failure, not a defect.
- Misuse and outside causes: flooding, a frozen unit in a garage, a blocked air intake, a power surge.
- Upgrades: a larger tank, a move from conventional vent to power vent, or tank to tankless. These restart the contract at a higher monthly rate and often carry an installation charge.
- Relocation, and a removal or buyout charge if you end the agreement.
Ask for any charge in writing before the technician starts, with the clause of the agreement it relies on. A charge that cannot be tied to a clause is one to dispute.
Calling your own technician on a rented unit
Your own technician is fine for diagnosis and for everything around the unit, and off limits for repairs to the unit itself. The equipment is the rental company's property, and most agreements say only its technicians may repair or alter it. An outside repair can leave you paying twice: once for the work and again when the company bills for unauthorised changes.
An independent TSSA-licensed technician earns the visit in three cases:
- A second opinion when the rental company says the venting or gas line must be upgraded at your cost before it will replace the tank.
- A no-hot-water call where the cause turns out to be the house: a tripped breaker on a power vent, a closed gas valve, a failed mixing valve.
- Work on what you own around the unit, such as supply piping, an expansion tank or a recirculation line.
Safety comes before ownership. For a gas smell or a carbon monoxide alarm, call Enbridge Gas or 911 first, no matter whose name is on the tank.
When a repair bill on a rental is the signal to buy it out
Rental fees for a tank run $25–$45 a month and rise with annual increases. A tank you own costs $1,200–$2,500 installed, and minor repairs on an owned unit under eight years old run $150–$800. So if the rental company quotes a large code-upgrade charge to replace a failed tank, compare it with ending the contract: you would be paying for that venting either way, and only one option stops the monthly fee.
Rented furnaces follow the same logic with larger numbers and longer terms. Read the term and the buyout schedule before accepting a free replacement, because the replacement usually starts a new contract. The arithmetic is laid out in how a water heater rental buyout is calculated.
For a second opinion on a code-upgrade charge, a diagnosis of the house side, or a price to replace a rented tank with one you own, ZK Mechanical's water heater service covers Burlington, Oakville, Hamilton and Mississauga. Call (647) 801-1252 or book a visit. The costs and buying topic page collects the other rental questions.