Tankless water heaters as the name suggests are basically water heaters without a storage tank. Also called as instant or demand-based water heaters heat and provide hot water as and when required, thus reducing standby heat loss and reducing energy bills. So a let’s take a look how exactly these modern water heaters work.
As the tankless water heaters don’t have a storage tank of their own they are directly connected to a cold water source of the house. Once the water flows into the heater, a flow sensor activates the gas burner or electric element which warm the heat exchanger unit. The incoming cold water goes over the heat exchanger and leaves the heater through the outlet as hot water. The temperature of the hot water is controlled by the heat exchanger which is in turn controlled by the thermostat.
The basic working principle of electric powered tankless water heater and gas powered tankless water heaters are the same, and only the power source and heating elements vary. There is additional exhaust vents provided for the gas based tankless water heaters.
We see that the tankless water heater starts functioning only when there is water flow in the pipeline and it is this particular feature of that makes them highly energy efficient. And continuous supply of hot water is ensured. A typical gas tankless water heater would have an output flow rate of 6-8 gallons of water per minute. This would be ideal for a shower or a faucet. But when you would want hot water at multiple points say bathroom, kitchen, washing machine etc. the output of the heater will not be sufficient. In such cases, we suggest going for two parallel heaters to match the load.