Do the math before you take on a tankless job

Some door-to-door sellers are going to homes and saying the rented water heater is unsafe and needs to be upgraded.

They may create the impression they're with the same firm that rents your current water heater.

Before acting, ask a few questions, such as:

• Who do you represent? What is the company's name?

• How long do I have to keep my water heater? (Some have 15-year contracts.)

• What will it cost to get out early? Is there a termination fee if I move or sell my house?

• What about installation costs? New gas water heaters often require extra venting to conform to standards adopted in 2007. Do I pay for venting or do you?

• Will you replace my hot water tank with a tankless unit? What are the benefits and the costs?

Tankless systems heat the water only when there is demand, unlike a conventional system that heats the water all day to maintain the tank at a consistent temperature.

As I said before, tankless units promise an endless supply of hot water. But that doesn't mean instant hot water.

You have to wait for the water to be heated in the basement and travel to your faucet.

Some models have a small buffer tank you can keep heated to speed the delivery of hot water. This eliminates the "cold water sandwich," which can drive you crazy when shivering in the shower.

There are those who feel the technology was oversold.

"Not a day goes by where I don't receive a call from an unhappy homeowner," said Paul MacDonald, national sales manager of Bradford White-Canada in Mississauga, which supplies storage and tankless water heater models.

"We're inundated with problems relating to improper selection or installation of tankless heaters."

Large households with high water use – running soaker tubs, multi-headed showers, washing machines and dishwashers at the same time – may be disappointed with a tankless unit.

If you want to go tankless, you can offset part of the cost with government and utility rebates.

You can get $315 from the federal ecoEnergy program and $315 from a matching provincial program. But you must get a certified energy audit before and after installation.

Enbridge offers a $300 on-bill rebate for an Energy Star-qualified gas tankless water heater if it's installed by August 31 of this year.

These rebates apply to the purchase or rental of a tankless water heater.

Bill Baird, Direct Energy's senior director of field operations, gave a cost breakdown to rent a tankless water heater. The monthly fee is $33.50, compared with $20.81 for an equivalent-sized power-vented rental tank for a family of three to four people who don't require high water flow.

When installing a tankless unit, you have to upgrade the gas and water lines going to the house, and change the venting.

About two-thirds of the installations done by Direct Energy are covered by the monthly rental fee. The remaining households will pay charges in the $500 to $600 range.

If you live in an area with high mineral content in the water, you'll need regular maintenance or water softeners – which may or may not be included in the rental fees.