Tankless Installation & Descaling · Waterloo

Tankless Water Heater Installation and Descaling in Waterloo

Tankless makes the most sense in the houses where a tank has stopped keeping up, and the least in the houses where it was never the problem. The install is mostly about gas supply and venting, and the ownership is mostly about descaling.

A tankless heater warms water as it flows through a heat exchanger, so there is nothing stored to run out of and nothing kept hot overnight. In a Columbia Forest two-storey with teenagers and a 40-gallon tank, that is a genuine fix. In a two-person household in Lakeshore with a tank that was fine, it is an expensive way to get what you had. We say which case you are in before quoting.

Gas supply is the first question

A whole-house tankless unit commonly draws 150,000 to 199,000 Btuh while running, against roughly 40,000 for the tank it replaces. The pipe from the meter was sized for the tank and the furnace together, and it frequently cannot carry the tankless load with the furnace running too. The run is measured, the existing loads totalled, and where the pipe needs upsizing that is in the quote. Whether the Enbridge meter and service can supply the added load is confirmed with the utility before the quote is final, because finding out afterward is how these jobs go wrong.

Venting, condensate and electrical

• Venting. Condensing units vent through plastic pipe to a sidewall or roof with clearances from windows and doors that open, soffits, the gas meter and the property line. On a west-side lot with a neighbour's wall a few metres away, the termination point takes some thought.
• Condensate. The exhaust is cool enough to condense, and the condensate is acidic. It needs a drain and normally a neutraliser cartridge first.
• Service valves. An isolation valve kit is what makes descaling possible without cutting pipe. A unit installed without one is a unit that will not be maintained.
• Power. The unit needs an outlet and does not run in a power cut, which is worth knowing before an ice storm.

Descaling in this water

The Region of Waterloo describes its groundwater supply as hard and says scale builds in appliances. A tankless heat exchanger has narrow passages and scales faster than a tank, until flow drops, the unit short-cycles and eventually shows a scale error code. Annual descaling is the answer: the unit is isolated at the service valves and a pump circulates a food-grade descaling solution through the exchanger for about an hour, followed by a flush and a check of the inlet filter and condensate neutraliser. On unsoftened water that is a yearly job. With a properly set softener it can stretch, but the filter and neutraliser still want a yearly look. Skipping it is the single most common reason a tankless unit fails early in this region.

Sizing against a Waterloo winter

A tankless unit is rated by litres per minute at a given temperature rise. Incoming water in February is cold, the rise needed is large, and the usable flow is lower than the summer brochure figure. Two showers and a dishwasher together is the honest test. In a student rental with five adults the test is harder still, and a tank or a pair of units is sometimes the better answer.

When we advise against it

Small household, sound existing tank, an awkward vent route, or a gas service that cannot carry the load without an upgrade the owner would rather not fund. In those cases a well-chosen power-vent tank is the better value and we say so.

Frequently asked questions

Serving Waterloo and surrounding areas. Contact us for a no-obligation quote specific to your property.