How Tankless Works

Rinnai tankless units heat water only when you need it.  So you save money and reduce waste by not heating and reheating the same tank of water.

• Rinnai tankless water heaters are placed in-line like a conventional tank-style heater. However, it does not continuously heat a tank of water that is waiting to be used.
• When opening a hot water tap, or starting the dishwasher, the Rinnai tankless water heater recognizes the need for hot water and starts the heating process.
• The temperature of the incoming water is used to calculate how much heat the burners must produce to deliver water at the desired temperature. This instant calculation maximizes the burners' efficiency.
• When the demand for hot water ceases the unit shuts down and uses no energy, waiting until more hot water is needed.
• This results in hot water that is not limited to what’s available in your tank, so you always have clean, hot water when you want it for as long as you need it!

Sequence of operation

• A hot water tap is opened such as a kitchen / bath faucet, shower, tub or washing machine
• The water flow through the Rinnai tankless water heater detects the call for hot water
• The water flow turbine sends a signal to the control board which looks at multiple factors:
  • Incoming water temperature
  • Desired water temperature as set on the temperature controller
  • Calculated difference between the two temperatures
• Depending on the calculated incoming and desired water temperatures, the gas flow into the burner assembly is modulated
• The electronic ignition sequence begins
• Water is heated to the desired temperature as it circulates through the copper heat exchanger providing endless hot water
• When the hot water tap is turned off, the tankless water heater sequentially shuts down and is placed in a standby mode pending the next call for hot water