Tankless water heater installation in northern Utah

It heats water only while a tap is open. ENERGY STAR describes the sequence: cold water enters the heater, a flow sensor turns on the gas burner, and the burner warms a heat exchanger that the water passes through. Exhaust leaves through a sealed vent.

Three things follow from that design.

• Output is measured in gallons per minute. The heater does not run out, but it can only heat so much water at once.
• Condensing models pull extra heat from the exhaust. They make condensate, so they need a drain.
• It needs electricity. Rinnai, one manufacturer, states that its tankless heaters will not operate during a power outage.

A small trickle of water may not be enough flow to turn the burner on.

It is a good fit for some homes and a poor fit for others. We would sooner tell you that at the estimate than after the install.

Tankless tends to work well when:

• the home has natural gas or propane and a workable route for the vent.
• the household wants long showers or fills a large tub.
• floor space is tight.
• someone will keep up with yearly descaling.

Think twice when:

• the gas line is too small and hard to upgrade.
• the heater would sit far from the bathrooms. A recirculation line may be needed to avoid a long wait.
• the power goes out often at your address.

Water here is hard. Provo's 2025 water report gives typical hardness of 10–15 grains per gallon. A tankless heater that is never flushed will scale up, so plan the maintenance before you buy.

Size it by the hot water you use at the same time, in gallons per minute.

ENERGY STAR gives average flow figures to start from:

• shower or bathtub: 2.5 gallons per minute
• clothes washer: 3.3 gallons per minute
• kitchen or bathroom sink: 2.2 gallons per minute
• dishwasher: 1.3 gallons per minute

Add up what runs together on a busy morning. Then account for two local conditions. Incoming water is colder in winter, so the heater has to raise it further and delivers fewer gallons per minute. Gas burners also put out less heat at high elevation, and the Park City weather station sits at about 6,900 feet.

We measure your fixtures and check the manufacturer's sizing chart for your elevation before we recommend a model.

ENERGY STAR says the installer should confirm the size, the gas line, the power supply, and the venting. Our process covers each one.

1. Estimate. We count fixtures, measure the gas line, and plan the vent and drain routes.
2. Permit. We check what your city or county requires.
3. Removal. We drain and remove the old heater and haul it away.
4. Mounting and gas. We hang the new heater and connect a gas line sized for it.
5. Vent and drain. We run the vent and air intake to the outside and pipe the condensate drain.
6. Water. We connect the water lines with service valves, so the heater can be flushed later.
7. Setup. We set the temperature and the elevation setting the manufacturer calls for, then test every fixture.

We finish by showing you the display, the filter, and the maintenance schedule.

Switching from a tank to tankless takes more work than a tank swap. We give a free estimate. The cost and the time depend on these things.

• Gas line. A tankless burner is larger than a tank burner. The existing line may need to be upsized.
• Venting. The old tank vent usually cannot be reused. A new vent runs through a wall or the roof.
• Condensate drain. Condensing models need one.
• Power. The heater needs an outlet nearby.
• Location. Moving the heater changes the water, gas, and vent runs.
• Size and features. Higher output and built-in recirculation add cost.
• Water treatment. A softener or scale filter is a separate choice.

Replacing an old tankless heater with a new one is a shorter job. Rebates or tax credits may apply, and we can point you to the current program. Financing is available.

Scale is the main threat to a tankless heater here. Provo's 2025 water report gives typical hardness of 10–15 grains per gallon, and Orem's report lists 7 to 25 in the city's own wells and springs.

A tankless heat exchanger has narrow passages and runs hot. Minerals bake onto the metal. Flow drops, the water temperature swings, and the heater shuts down on an error code.

Three things keep scale in check:

• Flushing. Rinnai tells owners to flush mineral deposits at least once a year. Follow the schedule in the manual for your brand.
• The inlet filter. We clean the screen during the same visit.
• Water treatment. A softener or a scale filter ahead of the heater slows the buildup.

We descale the heat exchanger through the service valves. If your heater has none, we can add them.

Tankless problems usually show up as an error code or as water that will not stay hot.

• Error code and shutdown. Common causes are scale, an ignition fault, or a blocked vent or air intake.
• Hot, cold, then hot again. Plumbers call it a cold water sandwich. It happens when the burner stops and restarts between uses.
• Temperature swings. Scale, a dirty inlet filter, or a failing flow sensor can cause them.
• No hot water at a low-flow faucet. The flow may be too small to start the burner.
• Water under the heater. The cause may be a leaking fitting, a failed heat exchanger, or a blocked condensate line.

When you call, read us the brand, the model, and the code on the display. If you smell gas, leave the house and call the gas utility or 911 first.