Let’s first think about how we typically store hot water in our homes or business. We use large 40-60 gallon tanks in our basements preheating water having it ready to use when we turn on a tap. Sounds good right? Well this is a huge waist of energy. No matter what you do during the day, that water tank is going to maintain the temperature of the water inside using energy. Every time the tank is used, cold water is dumped back into the tank causing the heating cycle to engage again. If the tank is drained and energy is used to reheat the entire tank, no hot water will be available to use during this time.
Before we weigh the pros and cons for choosing a tankless water heater, lets quickly review how it works.
How does a tankless water heater work?
- A tap is opened asking for hot water
- The flow sensor activates deciding how to heat the water
- The igniter engages
- The gas valve is engaged providing the right amount of fuel to the burner
- The fan and venturi activate to provide the correct amount of gas and fuel
- The burner ignites the fuel generating heat
- The secondary heat exchanger pre-warms the cold inlet water before sending it to the primary heat exchanger
- The control board adjusts the burner heat and sends out hot water at the desired temperature.
The pros and cons
- On-Demand, no wasted energy storing water
- Much higher efficiency
- 80% Smaller size and wall mounted
- Easy maintenance
- Endless hot water
- Very quiet
- Easily converted to propane
- Higher upfront investment cost
- Homes or business with very high hot water demand may require a buffer tank or more than one unit installed in cascade.