What Size Tankless Water Heater Do I Need

Are you impressed with the unique features of a tankless heater? But don’t know what should be the accurate size of a tankless water heater as per your needs, then read this entire informational guide for the right decision.

You must determine a few crucial factors to calculate the hot water supply in every faucet and showerhead of your living space. You can choose either electric or gas heating format according to your location.

Once you accurately figure out these measurements, you will see how this utility works wonders for you. Read on to learn all the key aspects of a tankless water heater.

 

How to Determine the Size of Tankless Water Heater – 4 Major Factors?

Suppose you want to precisely figure out the size of your small tankless water heater. In that case, you must know that no specific water heater size calculator is available that instantly shows your accurate results.

You need to consider a few factors which depend on the size of this small water heater; even if you have a larger family, you must still apply this set of rules to your selection criteria. Let’s figure out these crucial elements in the initial stage:

1. The Size of Your House

You can easily get any size of tankless water heater to give the water supply to every corner of your home. The important concern here is to figure out the exact area of your living space.

You must estimate the bathroom and kitchen fixtures where you need this water supply. It’s a better option to choose a larger tankless water heater than your assessed valves so that you will never see any shortage of hot water in these spots.

 

Some householders might require this supply in their bathtubs but ignore considering this and later get less output from this utility than other bathroom fixtures.

Hence, you must consider this utility to every sink and evaluate this quantity of water supply accurately or above the point so that you will never see any shortage.

2. Determine the Water Flow Rate

You also need to figure out the rate of this water output coming from this machine. Your home taps will answer you accurately about this rate.

You can check the water flow by opening different taps in your living spaces and checking its speed at one or multiple shower heads simultaneously. Some homeowners ignore calculating this rate and, in the end, find slower water pressure when opening multiple taps.

You must check this speed from different sink faucets, bathroom taps, and various shower heads in your bathroom. You might see variable speeds in these fixtures, but you have to focus on the overall water flow rate of the entire house.

If any showerhead gives you 1.5 gallons of water in a minute and you want this same flow in your two fixtures, then you require at least a 3.0 GPM tankless heater flow rate or a bit higher than this for perfect water flow in these two showerheads at the same time.

Showerhead 1 (1.5 GPM) + Showerhead 2 (1.5 GPM) = 3.0 Total GPM

This will give you a better idea about purchasing the accurate size tankless water heater for your complete living space. Now, you can calculate your bathroom faucets, kitchen taps, and other showerheads installed in the entire living space in the same way.

3. Temperature Level

After evaluating the flow rate of various faucets and taps, now you must figure out the heating level of this tankless water heater. Obviously, you need several temperature levels in every faucet, depending on its usage.

Some of the taps of your kitchen may require lower temperatures, while your bathtub showerhead needs variable temperature levels. Let me assume that you require 60 degrees Fahrenheit in the same showerhead where you want a 1.5 GPM water flow rate; then, you can calculate this scenario as under:

If the incoming water temperature is 45 degrees, then you need at least 105-degree Fahrenheit from the tankless water heater to deliver this 60-degree temperature to the showerhead.

It is better to get an automatic temperature adjustment option for this utility so that the machine can calculate the temperature size according to the demand of its consumer.

4. Your Household Size

You can calculate the tankless water heater cost and size according to the capacity of your household. Of course, you don’t need the services of your tankless water heater all the time, but still, you need to estimate according to your max usage.

The capacity of a tankless water heater for a shower can occasionally increase due to guests’ arrival or occasional gatherings.

Moreover, there are peak hours when everyone is looking to gain hot water, so you should calculate your household size for the tankless water heater very wisely and according to your requirements.

What does a Tankless Water Heater Do?

If you are using a classic tank-style heater in your home, the good news is that you can easily get a tankless water heater. This format of a water heater never stores the water in it; in fact, it is a slim utility that can easily install on any corner or hand to the wall providing the right flow of hot water in any faucet or showerhead.

This utility is powered by electricity or natural gas. Here, you have the option to install multiple water heaters as per your demands, and these utilities can work together to provide hot water all the time.

Some modern water heater products are efficient enough and will never waste hot water due to their supplemental heat recirculatory feature.

Electric Tankless Water Heater or Gas Format – Which Way to Go?

Besides all these crucial factors about the size of a tankless water heater, you also need to choose your preferred water heater, which is available in two formats.

You can get a home depot tankless gas water heater or pick the whole house tankless electric water heater to facilitate all of your family members.

If you are looking for one pick from tankless water heaters, gas or electric, then honestly, this electric utility is a far better option than the gas format due to the following motives:

Unit Price and its Installation Cost

The most valuable benefit of an electric tankless water heater over gas is its lower cost and easy-to-install feature. If you compare the tankless water heater prices of both these formats, you will find that the electric models of this utility cost you around $500 to $700.

While the gas water heaters range from $1000 to $ 1200. Similarly, the installation cost of an electric water heater is not as much of a gas heater.

Power Consumption and Maintenance

The electric water heater takes less power than the gas unit, another plus point of this utility. Moreover, it’s quite easy to maintain the electric water heater. The repairing cost of the gas-powered heater is also quite higher.

Energy Efficient Option

If you compare these formats of tankless water heaters in terms of energy consumption, you will find that the electric heater is more efficient in this scenario.

Besides this, if the gas source is inexpensive in your region than electricity, you can save some money from an efficient electric energy source.

Requirement of Upgradation

The electric tankless water heater needs significant upgrades; sometimes, you even need to install new electric sub-panels on high-output water heater machines.

In the case of every 2 GPM water, you must require a separate electric panel for this output. The gas water heaters can easily produce bulk hot water without installing the new heating elements.

Take a Closer Look at Maximum Water Flow and Realistic Maximum GMPs

Honestly, the maximum GMPs offered by most tankless water heater brands are quite lower, so you will get lower values according to your expectations.

The major reason for this discrepancy is the water stored in your pipes and their temperature. This temperature level is variable according to your location; if you reside in a cold area, this tankless water heater utility might require more heating time.

This issue is also dependent on your usage; if multiple family members are simultaneously accessing the hot water, then this utility might take more time to provide your desired hot water level. You must watch these realistic GMPs according to the maximum water flow for a perfect purchase.

Pros and Cons of Tankless Water Heater

You also need to understand the benefits and challenges of this utility so that you have an exact idea about this tankless format of a water heater, and you will get hot water anytime at every corner of your living space:

Pros

• The smart design of every unit takes less space
• Hot water will never waste with this utility
• No need to hang around the bulky tanks
• You never need to wait much for hot water
• Easy to install and maintain this machine
• Upgrading is not required very often

Cons

• No reserved hot water in its tank
• High prices with huge investment upfront

FAQs – Frequently Asked Questions

How Do I Know What Size Tankless Water Heater I Need?

To determine the accurate size of your tankless water heater, you must calculate the capacity, water flow, temperature rise, and household usage for a perfect purchase.

You can integrate these factors with the size of this water heater to precisely calculate the size.

What Size Tankless Water Heater Do I Need for a Family of 4?

The tankless water heater is available in electric and gas formats; if you have a family of four, you will require at least 8-10 GPM hot water. If you are interested in an electric water heater, you should go for a 20-28 kW water heater to fulfill your desires.

How Many GPM Do I Need for a Family of 4?

You need at least a 7 to 8 GPM tankless water heater for a family of four. You may require a higher GPM gas heater if you have multiple hot water appliances.

It is better to get an 8-10 GPM gas heater so that all persons can simultaneously use this utility without any shortage. If you want to invest more, you can consider a 10 GPM tankless water heater or higher.

Can My Tankless Water Heater Be Too Big?

You have to choose an appropriate size tankless water heater. It shouldn’t be too short or too big and suitable for your household needs.

What is the Downside of a Tankless Water Heater?

You will face some challenges with a tankless water heater. Some of the important cons of this utility are:

1. 1. Higher upfront charges
   2. Take time to deliver hot water
   3. Provide an inconsistent hot level of water, excessive use
   4. The extra burden of increased electricity charges
   5. Can’t provide hot water during a power outage

 

Final Thoughts

Now, you can easily calculate all the measurements of your tankless water heater on your own. Here, we have tried to cover all the key aspects of a tankless water heater; our influence mainly surrounds its size.

You should wisely measure the tankless water heater’s size after considering several important factors. Our experts have suggested an easy-to-measure water heater size calculator that gives you the luxury to precisely measure this size.

Most homeowners prefer electric tankless water heaters for their routine use on gas formats of this utility because of some attractive benefits of an electric one.