Gas Water Heater Line in Barrie

Gas lines for tank and tankless water heaters

Tank vs tankless: why the line size changes

A conventional gas tank keeps 40 or 50 gallons hot with a burner that typically draws around 30,000 to 50,000 BTU/h. Demand is modest and steady. A tankless heater has no stored water to fall back on: it heats water from cold as it flows, and many residential models are rated up to 199,000 BTU/h. On a January morning, with a shower and the dishwasher running and the incoming water near freezing, the unit fires close to that maximum. A half-inch line that fed a tank for twenty years often can't deliver that volume without a pressure drop, which shows up as lukewarm water, error codes or a heater that shuts down. So tankless installs often need a 3/4-inch or larger line back toward the meter, depending on the length of the run and what else is on the system.

Converting from electric to gas hot water

Switching from an electric tank starts with three questions. Is gas already in the house? Can the new heater vent from where you want it? Can the meter and main carry the extra load? If you already have a gas furnace, the answer to the first is yes, and the job is mostly a branch line, a vent and the connection. Many Ontario water heaters are rentals, so if yours is, contact the rental company about returning the old tank before the new one goes in. Power-vented tanks and most tankless units also need a 120-volt outlet nearby for the fan and controls.

Venting considerations that affect where the line runs

Venting drives the whole layout. A conventional atmospheric tank vents up an existing chimney or B-vent, so it has to sit close to that chimney. When a high-efficiency furnace is installed and the water heater is left alone in an old masonry chimney, that chimney often needs a liner. Power-vented tanks and most tankless units vent out the side wall through plastic pipe, which frees up the location, but the vent terminal has to meet code clearances from windows, doors, air intakes, the gas meter and the property line. Condensing tankless units also need a drain for their acidic condensate. We confirm the vent route first, then plan the gas line to the heater's final position.

Running a branch off the existing main

In most basements the gas pipe from the meter runs along the joists as a main trunk, with branches to the furnace and other appliances. For a new or larger water heater, we usually tee into that main and run a dedicated branch to the heater, with a shutoff valve and, where the manufacturer or code requires it, a sediment trap at the inlet. Before cutting in, we confirm the trunk can carry everything downstream once the new load is added. If it can't, which is common when a tankless unit joins a house that already has a furnace, range and dryer, the fix is a larger section of main or a separate run from the meter. The quote shows which one your house needs and why.

Where the gas fitter's work ends and the plumber's begins

We're licensed gas fitters. Our scope is the gas piping, shutoff valve, appliance connection, venting, leak test and start-up. The water side is plumbing: the cold supply and hot outlet, the temperature and pressure relief discharge line, any expansion tank or mixing valve, the drain pan, and on tankless units the isolation valves used for descaling. On a replacement or conversion, the two trades work on the same day or back to back, and we set the timing with your plumber so you're without hot water for as short a time as possible.