tankless water heater faq


What exactly is a tankless Water Heater?

A tankless water heater is basically what it sounds like….a heater that heats water on-demand unlike the more “traditional” systems that hold a huge tank of water that’s constantly being kept hot. The appeal of tankless water heaters is mainly efficiency (which translates to real savings over time). Because you only heat water as you need it, you’re not constantly paying to keep water hot.

What is the downside of a tanklesss water heater?

The biggest downside is frankly the cost.  Tankless water heaters will likely save you a lot of money in the long run but they’re not cheap.  That’s why it’s important to estimate how much hot water you’ll need and buy accordingly.  A 3bd vacation home will likely need much less hot water at any point in time vs. a 3bd primary residence. The second biggest downside is making sure you get the flow usage right. Because water is being heated on-demand, smaller units may take a longer to heat the water and may not have enough power to provide hot water for a shower and the dishwasher at the same time (for example). This is probably the biggest mistake people make when buying a tankless water heater….not accurately estimating their usage.

How much Hot Water do I need?

It obviously depends on how big your family is, how often you’ll be using (full time home vs. vacation home) and what your max usage will be. But as a rule of thumb, if you’ll be running 2 showers at the same time, you’ll need roughly 5 gallons of hot water per minute from your tankless water heater.

best tankless water heaters reviews Gallons per minute
Identify your maxium gallons per minute (GPM)

Is a Tankless Water Heater Worth It?

how much money do you save with tankless water heater?

Lower energy bills and saving space are the two biggest reasons people switch to tankless water heaters…but (as with anything that’s worth it), it comes at a cost. Tankless water heaters will cost you about 3x more than traditional storage heaters. This means, for a gas-powered “whole-house” version, you could be paying over $3k to go tankless.

BUT – According to Energy.gov, “For homes that use 41 gallons or less of hot water daily, demand (or tanklesswater heaters can be 24% to 34% more energy efficient than conventional storage tank water heaters.”

The Department of Energy estimates that gas-fired tankless water heaters save at least $100 per year relative to traditional tank water heaters. Electric tankless heaters will save at least $40-$50 per year but as high as $100. A good rule of thumb is to expect to get the space savings immediately and the economic savings over a 10 year period.

benefits of tankless water heater

What are the advantages and disadvantages of a tankless water heater?

pros and cons of tankless water heaters

Where can a Tankless Water Heater be Installed?

This depends on the type. The smallest tankless heaters are the electric versions. These are known as “point-of-us” units and depending on the model can fit right under the sink in which they’re going to be used. That’s why electric tankless water heaters are popular for RVs. The gas-powered versions are larger because they require space for the burners and vents. But event the biggest, whole-house gas versions would be no larger than a regular-sized suitcase so could be installed in alot of creative places around a home (including where your traditional tank water heater is).

How Much do Tankless Water Heaters Cost?

The rule of thumb is about 3x as much as your traditional water heater (for a “whole-house” model). Obviously the smaller electric versions are cheaper but may only be suitable for an RV or small cabin.

On average, a whole-house replacement (gas-powered) tankless water heater can run you close to $3k.

how much does tankless water heater cost?

What is Whole House vs. Single Point Water Heater?

whole house vs point of use tankless water heater

Let’s start with Single Point…this is what it sounds like. Small, tankless units that are electric (usually) and need to be installed adjacent to the appliance that will need the hot water (and the electric source that will power the unit). That means if you’ve got a dishwasher and a bathroom, each will need a separate single-point unit. That’s why these versions are popular with RVs and smaller vacation homes (like cabins). The upside, is they’re typically really inexpensive.

Whole-house units are gas powered and can truly replace a traditional water heater by delivering hot water to an entire house. These units are bigger than single point (obviously) but still not huge (smaller than a traditional water heater) and usually installed outside the home. These units are more expensive (about 3x more expensive than traditional) but will save over $100 a year in energy costs.

A single point system will generally deliver about 0.5 to 2 gallons per minute (GPM) while a whole-house system will deliver about 5-10 GPM. The GPM number is crucial to understand before you buy…remember you need to think about the MAX GPM at any point …not the average. If you’ve got a house full of teenagers that will be running multiple showers at once, then you’ll need a higher GPM unit.

How Long does a Tankless Water Heater Last?

The good news is that tankless water heaters are generally more durable than traditional. They have longer lifespans and longer warranties. A tankless water heater should last, on average, over 20 years vs. only 10-15 for a traditional water heater.

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

The short answer is “No”. That’s one of the biggest benefits of a tankless water heater. BUT – it depends what kind of Gallons per Minute your tankless water heater is capable of vs. what’s being demanded. Even the biggest and best gas-powered whole-house systems will struggle to heat 3 showers, a dishwasher and 2 sinks indefinitely.

Can a tankless water heater fill a tub?

Again – depends on the size. A smaller electric tankless heater can take a long time to fill up a tub while a larger gas-powered “whole-house” unit will have no problem.