How Does a Recirculating Pump Work On A Tankless Water Heater

How Does a Recirculating Pump Work On A Tankless Water Heater

When we talk about tankless water heaters, the first thing to come to mind is the fact that they don’t have a tank. Therefore, you don’t worry about energy heating the water over and over again until you need it.

However, there’s a catch to it, as hot water will have to travel from several taps. Therefore, it’s going to take more than a second for the water to get warm. You waste both time and money, with water running down the drain. Sure, there are simple solutions, such as collecting the water in a bucket as you wait for the hot water to come out. You can use the collected water for your plants later on, but isn’t this similar (to some extent) to using a tank?

How to solve the waiting time problem?

The solution comes from the recirculating pump that maintains the heater water in the tap, making it available for the shower or sink almost instantly.

In order to understand the importance and working mechanisms for recirculating pumps, you need to keep reading. By the end of your reading, you’re going to head the first hardware store for buying a recirculating pump.

What’s the best way to depict the recirculation pump for a tankless water heater?

Also known as the circulator pump, the recirculation pump is continuously circulating the water back to the tankless water heater for later reheating. It’s not the cheapest way to increase the energy efficiency of your tankless unit, but it does prevent the water from cooling off. Thanks to it, the water will be hot next time you’re turning on the shower or the tap.

The system is designed for circulating the water between the heater and the fixtures attached to it.

What does a recirculation system include?

A recirculation system consists of three main components:

  • The water heater and the pump, individually or connected.

You can find tankless water heaters that come with built-in recirculation pumps, and models that come with an external pump. There are also the units that allow programming the external pump for peak water usage periods.

  • The recirculation method

There are actually two methods with this one, with the first one including a specialized return line for circulation. Therefore, your household will have not two, but three pipes: hot, cold, and recirculation. It’s a reliable choice if the plumbing is new or if you have a one-story home with pipes easy to access.

When a recirculation line isn’t available, you must mount a bridge valve at the furthest fixture. This way, the cold water line will cycle the water back to the tankless water heater.

  • The control you gain when the circulation pump is running

You may use a timer for turning the recirculation any now and then. Another way is using a thermostat or aquastat that turns on the pump, maintaining the desired temperature of water in the line.

It’s quite common for recirculation pumps to come with a built-in timer or aquastat.

How does the full recirculating pump system work?

You have to install another pipe made for hot water. So that the system goes to a loop from the water heater to the faucet and back again. The pump draws the remaining hot water back through the loop so that you get hot water when tapping the hot water. There will be no more water in the pipes to get cold, and you no longer wait for the water to get hot.

Numerous models of pumps feature sensors and timers, with the sensor turning the pump off when the hot water circulates through the loop. The timer lets you control the activity of the pump. Therefore, you may set it to shut off at night when you’re not home or when you’re on vacation.

What’s to say about the recirculating pump comfort system?

This system includes the cold water pipe for circulating the left water back into your unit. It’s an affordable choice for anyone losing patience while waiting for the hot water to come out. The system runs hot water fast to areas in your home that typically require more time to get the hot water.

You don’t need an additional pipe for this system, which only makes it more affordable. It has some shortcomings, though. Since the hot and cold water shares the same pipe, the water may end up being lukewarm or needing some time to get cold.

Some of you may not be aware that you’re already using a recirculating system. Maybe the previous owner unplugged the pump, so you need to see if you still have it. Get in touch with your plumber to find the pump and make it functional again. It’s not a bad idea to check the top or bottom of your water heater before calling the professional help.

What prices should you expect?

It’s better that you also take a look at the costs for each recirculation technology before you decide:

  • Tankless water heaters with built-in recirculation pumps

expect to pay somewhere between $250 and $415 more for a unit with a recirculation pump. It’s the best option when you’re installing a new tankless water heater, saving you the costs for pump installation later on

  • Buying recirculation pumps separately

If you’re using a tankless water heater without a pump, you need to buy a pump. You may pay somewhere between $235 and $400 for a pump, depending on the size. If you can install it on your own, your spending will be lower. Otherwise, you need to add $125 to $300 for installation.

  • Complete kits

Should you choose not to mount a recirculation pipe, the bridge valve is a viable choice as well. It’s only $25, but you can go with a complete kit that includes both the pump and an aquastat. A package of this kind ranges from $250 to $450.

  • Recirculation line

When you install the line and the plumbing at the same time, you will pay from $75 to $300 for the line. Should you install the line afterward, you will pay even more than $1,000.

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