How to Select the Right Size of Tankless Water Heater for Kitchen


In recent time, tankless water heaters have become one of the most popular home appliances to almost every single home owner. Tankless latest heaters comparatively last longer and very easy to install. At the same time, they are nearly maintenance free. So, homeowners rush to tankless heaters instead of going for a conventional one. Yes, some people claim that electric tankless water heater takes a bit long to heat up the water, especially when it is of large amounts. But the truth is- most of them can’t choose the right size according to their need. Wondering, how to select the right size tankless water heater for kitchen? Let us guide you step by step in the following.

Choose the Mounting Area

The first thing you need to do is- selecting the space where you want to install the tankless water heater unit. Tankless units are incredibly smaller comparing to the units with storage tanks. Therefore, you don’t need to worry about the space. Usually, a tankless unit is as small as around 10” by 7” height/width. So, you can easily install a tankless unit in a very tiny space, even on a wall as well.

Measure Cold Water Temperature:

Now, measure the temperature of your cold water using a thermometer. At this point, you need to be very careful because your water heater will be heating this cold water to your desired temperature. While measuring, ensure that your tankless unit will be able to maintain the temperature you want even at the maximum flow rate.

For example, shower hot water is commonly desirable at 104 F. Now if the temperature of your cold water flow is 54 F, your water heater unit need to be capable of providing 60 F. higher than the incoming cold water to offer you a warm shower at the maximum flow rate.

Calculate Water Flow Rates

Now, it’s time to calculate the water flow rate. You need to determine how many gallons of hot water you will be in need at a particular time. Have a look at the chart below and calculate the total amount of water you need simultaneously.



For example, if you want to run a shower and kitchen sink simultaneously, you will require 4 gallons of hot water every single minute.



Calculate the Water Heater Size

It is the final stage, and you need to consider the factors mentioned above to calculate the size of your water heater unit. Now, get started with determining the temperature of your incoming cold water, calculate the flow rates, and do this simple math.

Total GPM (Gallon per Minute) + Desired Temperature = Your Tankless Unit

Let us explain you a bit!

See, the temperature of your incoming cold water is 55 F. You need a shower that requires 1.5 GMP, and at the same time, your wife needs to run the kitchen sink that requires 1.5 GMP. The desired temperatures in this situation are 104 F and 110 F respectively. In this case, you will be in need of heating 55 F to 110 F on average and the total 3 GMP at that moment. So, to keep pace with the functions and desired temperature you need a tankless unit that can raise the temperature of incoming water to 55F at 3 GPM.

Leave a Reply

Your email address will not be published. Required fields are marked *