How to Get Hot Water Faster from Tankless Water Heater

A tankless water heater is aptly named for its lack of a “tank” to store water (as you’d find on a traditional water heater). A tankless water heater heats the water as it passes through the unit. For this reason, it is often called an “instant” water heater.

However, as users of this device will tell you, it isn’t always so instant. In this article, we’ll examine just how fast these units can heat your water, and the various methods you can take to increase this rate.

get hot water faster from tankless water heater

How do I make my tankless water heater heat faster?

There are a couple of reliable methods to get your tankless water heater to heat your water faster. The first important caveat is that a lot of this will depend on the quality and power of your individual unit. The more powerful the unit, the faster it can heat the water.

That being said, you can also use a recirculation system to create a loop in your plumbing, keeping your water hot for instantaneous use. You can also purchase a point-of-use water heater to complement your tankless water heater. Both solutions are rather extensive, and we’ll break them down in further detail below.

Related: Rinnai vs Rheem Tankless Water Heater: Which is better?

How to Get Hot Water Faster from a Tankless Water Heater

Unfortunately, there’s no “quick fix” to get your tankless water heater working more efficiently. You are mostly constrained by the power of the unit itself. If your tankless water heater can only heat water so fast, then you’re basically stuck at that rate without modifications to the system. Here are two of the more popular modifications to get hot water faster:

Related: What is a “dip tube” and why do tankless water heaters not need them?

Method 1: Recirculating Pump

After water passes through a tankless water heater, the hot water travels through your pipes to the faucet or tap of choice. Therefore, when you turn off the faucet, the water in the pipes is left to cool off. Depending on the distance from your tankless water heater to the faucet, you may have to wait for a fresh supply of hot water each time you turn on the tap. A recirculating pump addresses this problem.

A recirculating pump takes the water in your pipes and circulates it back to the water heater. Basically, you are creating a “dedicated loop” between the tankless water heater and various fixtures in your home.

A thermostat tests whether the water in your pipes has become cold, and automatically circulates it back to the water heater, keeping your water hot and eliminating the “waiting period” to receive hot water. The result is that you get hot water much faster and without the wait.

Many tankless heaters are built with a recirculating pump included. But many tankless heaters are also incompatible with a recirculating pump. Therefore, if this is important to you, be sure to buy one with this capability!

Additionally, because you are creating a loop from the water heater to the fixtures, there may be extensive work required. If you don’t already have this plumbing installed, it can be a costly installation because not only are you installing the pump itself, but you’re also installing the “loop” in the plumbing.

If you are looking for a way to avoid the expense of installing a loop, then our next method may make more sense for you.

Related: Rheem Water Heater – Ultimate Trouble Shooting Guide

Method 2: Secondary Water Heater

As opposed to a recirculation loop, you can also purchase a secondary water heater for any faucet or tap where you prefer instantaneous hot water. This is usually referred to as a “point-of-use” water heater, which is a small water heater that is attached right near a faucet, shower head, or other tap. This water heater serves to heat any cold water left in the pipes, while the primary tankless heater is generating hot water from below.

Typically, a secondary water heater will be less powerful than your primary heater, and it’ll simply serve to fill the gap while your primary heater is getting your water up to temperature.

Hot water with shower


Thanks for checking out our guide to tankless water heaters. In this article, we addressed one of the most common areas of concern related to these popular water heater designs. A tankless heater is a great way to save space and money, but there are some definite downsides over a traditional design. As you can see, with some crafty plumbing and some ingenuity, you can ensure instant access to hot water at all times.


Before we wrap up, let’s check out some common questions about tankless water heaters:

Does it take longer to get hot water with a tankless water heater?

Compared to a traditional water heater, a tankless water heater will generally take longer to output hot water. This being said, it also depends on the power and efficiency of the unit, and whether you have a recirculating pump/loop installed (see above).

The reason a tankless water heater tends to be slower is because it does not have a tank to store excess hot water. Traditional units fill a tank with hot water beforehand, giving you instant access to a certain amount of hot water (depending on the size of the tank).

Why does my tankless hot water heater go cold?

Your tankless hot water heater likely goes cold because, after the water passes through the heater, it has to sit in your pipes before it is dispensed from your faucet. Therefore, you will actually need to wait a little while for the tankless water heater to heat the water, before you can dispense hot water. Before the hot water arrives from the tankless water heater, you may get a burst of cold water that has been sitting in the pipe.

Alternatively, there may also be a problem with the unit itself. Check your unit to ensure it is running properly, and that you have not accidentally turned it off. If the unit is defective, then it is often cheaper to replace the unit than to try to fix it, but it depends on the issue.

Leave a Comment

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