It is a system that heats water on demand, without storing it in a tank. It uses either gas or electricity to heat water as it flows through a heat exchanger, which transfers heat from a burner or an element to the water. A tankless water heater can provide an endless supply of hot water, as long as there is enough fuel or power and water pressure.

It can save you energy and money, as it only uses fuel or power when you need hot water, unlike a tank-style water heater that constantly keeps water hot.

A tankless water heater can also save you space, as it is much smaller and can be mounted on a wall or in a closet.

They can also last longer than a tank-style water heater, as it has less risk of rust, corrosion, leaks, or explosions.

This technology can also provide better water quality, as it does not store water that can accumulate sediment, bacteria, or minerals.

The size of a tankless water heater depends on the flow rate and the temperature rise of the water.

The flow rate is the amount of water that you need at one time, measured in gallons per minute (GPM).

The temperature rise is the difference between the incoming water temperature and the desired output temperature, measured in degrees Fahrenheit (°F).

To choose the right size of a tankless water heater, you need to add up the flow rates of all the fixtures that you want to use simultaneously, and determine the temperature rise based on your climate and preference. Then, you need to compare these numbers with the specifications of different models of tankless water heaters, and choose the one that meets or exceeds your needs.

The water heater requires proper installation and maintenance to ensure its safety and efficiency.

A gas-powered tankless water heater needs a gas line, a venting system, and an electrical connection.

An electric-powered tankless water heater needs a hardwired connection to the circuit breaker or electrical panel.

Depending on the size and location of the unit, you may also need to upgrade your gas or electric service, install new pipes or valves, or add insulation or expansion tanks.

It is recommended to hire a licensed professional to install your tankless water heater according to the local codes and manufacturer’s instructions.

A tankless water heater also needs regular maintenance to prevent scale buildup, corrosion, or damage. You should flush and descale your unit at least once a year, replace the filters and valves as needed, and check for leaks or signs of wear and tear.

You should also follow the manufacturer’s recommendations for cleaning and servicing your unit.

At a point in time, the water heater can experience some issues that affect its performance or operation. Some of the common problems are:

• No hot water: This could be caused by a power outage, a tripped circuit breaker, a faulty igniter or flame sensor, a low gas pressure, a clogged heat exchanger, or a frozen pipe.
• Not enough hot water: This could be caused by an undersized unit, a high demand of hot water, a low water pressure, a dirty filter or aerator, a faulty thermostat or sensor, or a mineral buildup in the heat exchanger.
• Fluctuating water temperature: This could be caused by an oversized unit, a low flow rate of hot water, a clogged showerhead or faucet, a faulty thermostat or sensor, or a cross connection between hot and cold water lines.
• Water leakage: This could be caused by a loose or damaged pipe fitting, valve, seal, or gasket, a cracked heat exchanger, an excessive pressure or temperature in the unit, or a condensation buildup in the venting system.