Asked by: Jaswinder Benaissa
home and garden home appliances

Can you run tankless water heaters in series?

Last Updated: 9th March, 2020

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Tankless electric water heaters can be installed in series.
Two Titan N-120 water heaters create very hot water, even at high flow rates during the winter.

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Also to know is, can you put two tankless water heaters together?

If the flow rate falls below a threshold both units will stop and the water will run cold. Rinnai has the lowest minimum flow but there is still no reason to double it. If you are planning to connect two tankless water heaters to each other, it is best to do it in series.

Beside above, what is the downside of a tankless water heater? Tankless water heaters produce an endless supply of hot water, take up less space, have a lower risk of leaking, are safer, and have a significantly longer lifespan on average. The main disadvantage of tankless water heaters is their upfront cost (unit and installation) is significantly higher than tank-style heaters.

Hereof, do I need one or two tankless water heaters?

For larger households that typically use more than 85 gallons per day, two tankless systems, or the largest available model, are likely needed. For smaller households that use under 40 gallons per day, one unit should suffice. They are miniature tankless water heaters designed for use at one outlet, such as a sink.

How many tankless water heaters do I need?

Average Temp. For example, if you are running 2 showers at the same time, you will need 5 gallons of hot water per minute from the tankless water heater. If you were running a shower and the washing machine at the same time, you would need 4.5 gallons per minute from the water heater.

Related Question Answers

Hermitas Dibbern

Professional

Can I preheat water before it goes through a tankless water heater?

The typical way to pre-warm water is to install a standard tank water heater before the tankless, but leave it turned off. Using an automotive radiator is a terrible idea. You don't want to connect something not designed for potable water to your plumbing. That's just asking for trouble.

Olmo Tepes

Professional

What is the best tankless water heater?

7 Best Tankless Water Heaters Reviewed
  • Rheem RTEX 13 Electric Tankless Water Heater.
  • Stiebel Eltron Tempra Plus 24 kW.
  • Rinnai RUC98iN Ultra Series, Concentric/Twin Pipe Installation.
  • Atmor AT-D18TP-AZ Instant Tankless Water Heater.
  • Ecosmart ECO 27 Tankless Water Heater.
  • Rheem RTGH-95DVLN Direct Vent Tankless Water Heater.

Izana Lindenborn

Professional

Do you need a tankless water heater for each bathroom?

Flow rates vary from about 1.2 to 6 GPM. Point-of-use models, such as those that provide hot water to a single bathroom sink, are rated 1.2 GPM. A 2.6-GPM tankless water heater will handle one shower at a time. A 4-GPM tankless water heater one shower and one sink, and a 6-GPM two showers.

Blay Brockmoller

Explainer

Is a tankless electric water heater worth it?

The U.S. Department of Energy estimates gas-fired tankless heaters save an average of $108 in energy costs per year over their traditional tank counterparts, while electric tankless heaters save $44 per year. Rewiring your house can easily add as much as $5,000 to the cost of installing a tankless water heater.

Luanne Rosendaal

Explainer

Is one tankless water heater enough for a house?

In most cases, the water should be heated to at least 120 F, so the home will need a tankless unit that can heat 2.5 gallons per minute by 70 degrees. Most propane or natural gas tankless water heaters on the market can handle a rate of 5 gpm at a 70 degree temperature rise.

Oktay Eyfriet

Explainer

How do you connect two hot water heaters parallel or series?

Series is where the cold water goes into one water heater then through the second water heater. Parallel is where the cold supply has a tee which feeds each water heater independently and joins them back together to one hot water supply.

Yackeline Dircksen

Pundit

What is the difference between point of use and tankless water heaters?

A Tankless water heater uses a heat source (electric or gas) to warm up cool water on-demand whenever you need it rather than storing hot water in a tank. Pros: Lower initial cost - A traditional water heater installation can be half as much as a tankless water heater.

Czeslaw Leizabe

Pundit

Can I install tankless water heater in bathroom?

Tankless water heaters can be installed anywhere inside your home. You can even have a tankless water heater in a bathroom! Some families with larger homes choose to install two, one for each floor, for example. Because of their small size, they fit in closets, cabinets, pantries or laundry rooms.

Evgeniy Grosshauser

Pundit

Which is better hot water heater or tankless?

According to Energy.gov, “For homes that use 41 gallons or less of hot water daily, demand (or tankless) water heaters can be 24% to 34% more energy efficient than conventional storage tank water heaters.” Tankless water heaters (if gas-fired) will save homeowners over $100 annually the longer they remain in service.

Eloysa Stuhldreyer

Pundit

What size water heater do I need for a family of 5?

3 - 4 people, you'll need at least a 50-gallon capacity tank (electric) or a 40-gallon capacity tank (natural gas or liquid propane). If your family size is 5 or more, you'll need an 80-gallon tank (electric) or a 50-gallon tank (natural gas or liquid propane).

Yueping Schroer

Pundit

Do you need a recirculating pump with a tankless water heater?

Faster Hot Water with Recirculation
No more waiting for hot water. With a dedicated return line, the integrated pump simply recirculates water from the tankless water heater through the line and back to the heater. If your home does not have a dedicated return line, which many do not, it can be very costly to add one.

Idalba Siegmund

Teacher

Iacov Leceta

Teacher

Can you oversize a tankless water heater?

As suggested when selecting a tank-type heater, you don't want to buy an oversized or undersized tankless water heater, as it will result in unnecessary issues such as the rising upfront price, operating costs and wasted water and energy - affecting your budget and time.

Pierpaolo Teunis

Teacher

Are on demand water heaters worth it?

According to the U.S. Dept. of Energy, a tankless water heater is more efficient and uses less energy than a conventional water heater, providing a $25 to $107 in annual savings. If your hot water use is low (less than 41 gallons per day), a tankless water heater will be 24% to 34% more efficient.

Jillian Bordonada

Teacher

How much does it cost to replace a hot water heater with a tankless?

A new tankless water heater costs between $1,500 and $2,000 installed, while a whole house tank costs between $600 and $800. A tankless hot water heater costs around $430 without installation and a traditional heater costs around $440.

Audaz Marinelli

Reviewer

What are the pros and cons of tankless water heaters?

Are Tankless Water Heaters Worth It? 10 Pros and Cons
  • Pro #1: Instant Hot Water.
  • Con #1: Inconsistent Temperatures.
  • Pro #2: Longer Lifespan.
  • Con #2: Higher Initial Cost.
  • Pro #3: Lower Month-to-Month Costs.
  • Con #3: Limited Hot Water Supply.
  • Pro #4: Space Savings.
  • Con #4: Additional Equipment is Often Necessary.

Antonello Lindegrun

Reviewer

How do you service a tankless water heater?

Steps
  1. Turn off the power source for your tankless water heater.
  2. Close and turn off the 3 water valves attached to your tankless water heater.
  3. Remove the purge port valve caps slowly from the purge valves located on each of the cold and hot water valves.
  4. Attach your hosing lines to each of the 3 valves.

Robby Absattaroff

Reviewer

Can you run out of hot water with a tankless water heater?

yes, there's a downside to this. Although a tankless system can't run out of hot water, it can be overwhelmed with demand. If more than one tap is on demanding hot water at the same time, however, such as other showers or a running washing machine, the water heater will struggle to keep up and drain extra power.

Jolita Schapermeyer

Supporter

How much water does a 20 minute shower use?

A low-flow showerhead uses about two gallons a minute, or 20 gallons for a 10-minute shower. A standard showerhead uses 2.5 gallons a minute, or 25 gallons for 10 minutes.