Tankless Water Heater Service in Eagle, ID

Flow rate and temperature rise set the size

A tankless unit is rated by how many gallons per minute it can heat by a certain number of degrees. Two numbers decide whether it works for you. Flow is how much hot water runs at once. Temperature rise is how many degrees the unit must add between the cold supply entering the house and your set point.

The DOE puts the ceiling for tankless hot water at roughly 2 to 5 gallons per minute. That sounds like plenty until two showers and a dishwasher start together. Winter makes it harder, because colder incoming water means the heater must add more degrees to the same flow. A unit that covers July can fall short in January.

We size by walking the house. We count the fixtures that can run at the same time, note the longest pipe runs, and check the cold water temperature at a tap on a winter morning. Then we match that load to the unit's rated output at your temperature rise, not the number printed for mild water.

Tankless or storage tank: a plain comparison

This table shows how the two designs differ on the points that matter most to a homeowner. The life figures and the output limit come from the U.S. Department of Energy.

If your household rarely runs more than two hot taps at once, a single tankless unit works well. If three or four run together most mornings, a storage tank or two tankless units may fit better. We will tell you which, even when the answer is a smaller job.

Gas line capacity, electric load and venting

Most gas tankless units burn far more fuel per hour than a tank heater, so the gas line has to carry it. Intermountain Gas Company supplies natural gas in Eagle, ID. We check the pipe size, the run length and the other appliances on the line before we pick a unit. A line that served a tank heater fine can starve a tankless unit and cause weak heat or fault codes.

Venting is the second check. Condensing units use plastic vent pipe and need a drain for the acidic condensate. Idaho's plumbing code, built on the 2015 Uniform Plumbing Code, wants a heater with Category 3 or 4 exhaust venting pressure tested as a whole, five pounds of air for fifteen minutes (section 503.1).

Garage installs have a height rule: burner and ignition source at least 18 inches up from the floor, unless the unit has a flammable vapor ignition resistant listing (507.13). That rule decides where a unit can hang. Electric tankless units skip the gas and the vent, but they draw heavy amperage, and your panel and wiring need room for it. We do not size electrical service, so that part is a job for a licensed electrician.

Flushing and descaling a tankless water heater

Minerals in the water collect inside the heat exchanger and slow the transfer of heat. A scaled unit runs hotter, cycles on and off, and may throw a fault code. A flush dissolves the scale and carries it out through a hose.

Most units have two isolation valves and two service ports on the water lines. We use those ports to circulate a descaling solution through the heat exchanger. The maker's manual names the solution and the time, because the wrong acid can harm internal parts.

1. Shut off the gas or power to the unit and close the hot and cold isolation valves.
2. Connect hoses and a small pump to the service ports.
3. Circulate the descaler the manual allows for the time it calls for.
4. Rinse with clean water and clean the inlet screen.
5. Open the valves, restore gas or power, and test hot water at a tap.

Flush timing depends on your water and the manufacturer's instructions, so check the manual instead of trusting a rule of thumb. In Eagle, ID, the supply may be Veolia Water Idaho, the City's own system or a private well, depending on the address. We do not know your hardness without a test. Your supplier's yearly water quality report or a tap test answers it, and our page on water softener and filtration options helps if scale is heavy.

Custom homes in Two Rivers and The Shores need a load count

Custom homes in Two Rivers (built roughly 2000 to 2017) and The Shores (2006 to 2019) were designed one at a time, so no two floor plans match. We count your fixtures and your simultaneous use instead of assuming a standard house. Sometimes the answer is two units, or one unit plus a recirculation line for a far bathroom.

Some original storage heaters from the late 2000s have reached the Department of Energy's 10 to 15 year range. That is often when owners start asking about a swap. If your heater is near that age, a tankless unit rated for about 20 years deserves a fair look next to a new tank.

Banbury Meadows homes went up in phases from 1994 to 2019, so heater age and gas line layout vary from house to house. A look at the existing gas pipe and vent path tells us quickly whether a swap is simple. For new builds in Star, where the population rose 91.9 percent from 2010 to 2020, we can size the unit during rough-in, and our Star service page covers that area.

What a tankless water heater does not fix

The phrase endless hot water is a little generous. The unit keeps heating as long as demand stays under its rated flow, and it slows down when demand passes that line. Know the limits before you buy.

• It does not raise water pressure. Low pressure is a supply or pipe problem, covered under water line work.
• It does not remove the wait at a far tap. A long pipe still holds cold water until the hot arrives.
• It can give a short burst of cold between two close uses, because the unit needs a moment to fire again.
• It does not soften water. Scale still builds, so plan on flushes.

If you want to compare designs side by side, our water heater installation page explains sizing for storage tanks too.

What moves a tankless water heater quote