Are you ready to commit to a water heater with no tanks and the promise of endless hot water? If so, you may wonder how long the installation will leave your home without hot water. Fortunately, installing a tankless heating system can take some days.

This article will explain “How Long Does It Take To Install a Tankless Water Heater” and what aspects contribute to the required time. If you use a tankless heating system, this information will help you better understand what to anticipate.

How Long Does It Take To Install a Tankless Water Heater?

Most tankless heating system installations include replacing an existing water heater with a tankless one. In this situation, allow the installation process to take four to six hours on average. 

Your expert may be able to finish installing your tankless heating system sooner than expected. Tankless installations normally take between three and six hours, finishing up on the earlier side. 

Your expert is not a magician, but he will try to respect your time while considering your installation’s needs. 

How Long Does It Take To Install a Tankless Water Heater

One must keep in mind that these are merely averages. Every home is unique, and there are numerous problems a technician can encounter throughout the installation that could increase or decrease the overall amount of time. Let’s look into what those could be so you stay aware of the situation.

Factors That Impact Tankless Heating System Installation Time

A certified professional must install a tankless heating system due to the complexity of the task and the requirements for proper operation. No matter what the needs of the installation are, having the correct individuals on the job guarantees you will get skilled assistance. 

1. Indoor vs. Outdoor

Installing a tankless heating system indoors rather than outdoors can lengthen the process. The indoor tankless heating systems need special venting, which is unnecessary for outdoor-mounted tankless heating systems. 

Workers typically need more room to move during indoor installations, which might lengthen the process. Due to this added effort, you should anticipate that your tankless heating system installation will take longer than usual. 

However, if you choose the outside option, your expert can finish the installation sooner. Simply put, being outside gives you more flexibility to roam about and doesn’t require any venting. 

2. Location of the Gas and Water Lines

Your water and gas lines also affect the time spent installing the tankless heating system. To securely install the tankless heating system, your technician might need to expand these lines. 

If so, it will take longer to complete the installation the further your tankless is from the lines. Your technician will connect the gas and water if they are already in the area. 

3. Tank-Style to Tankless Vs. to Tankless to Tankless

Every changeover with a water heater is unique. Tankless heating systems are becoming increasingly popular, and some customers may replace their existing models with newer, more efficient ones. 

How Long Does It Take To Install a Tankless Water Heater

Depending on your circumstances, the installation time for a tankless heating system will vary. It may not be necessary to run new lines or build new vents when switching from one tankless heating system to another, which can speed up the installation process. 

On the other hand, switching from a water heater with a tank to a tankless heating system is a bit more work because you will need new vents and may have to make new connections for your gas and water lines. 

4. Appropriate Whole-House Water Shut-Off

For a licensed professional to install your tankless heating system properly, they will require access to the main water shutoff for your home. One of two factors will slow the installation if you don’t have an excellent whole-house shut-off. 

Sometimes, your technician may need to turn off the water supply to your home. This extra installation might take a while but might be useful for later jobs. 

On the other hand, to have the water to your home turned off, your technician might need to speak with the city directly. Additionally, contacting the city is time-consuming and without any potential rewards.

Costs Affecting the Installation of Tankless Heating System 

The price of installing a tankless heating system depends on four primary factors:

  • Brand: The cost of any system or appliance for the home is significantly influenced by branding. Newer products like EcoSmart typically charge less than established luxury ones like Noritz.
  • Fuel source: A water heater’s price is significantly influenced by its fuel source. More straightforward choices, like an electric tankless heating system, cost less upfront but can cost more in the long run. On the other hand, more energy-efficient alternatives, such as tankless heating systems powered by the sun, will set you back more money initially but will save you money on your monthly energy bills.
  • Labor: Depending on the area, technicians charge between $50 and $150 per hour. Depending on the heater’s kind, location, and fuel source, installing a tankless heating system might take two to eight hours. You should anticipate additional costs of about $200 if your installation needs more repairs or painting.
  • Size: The size affects installation costs for tankless heating systems significantly. The price of a water heater increases with its size.

Additional Financial Factors

There are more aspects to be aware of that could affect the overall cost of installing a tankless heating system than the four major cost concerns mentioned above. 

1. Accessibility

The cost of removing your old water heater and installing the new one may increase if it’s in a hard-to-reach location. For instance, installing a water heater inside an attic or a confined space will be more expensive than installing one in a wide-open basement.

2. Location 

Tankless heating systems come in indoor and outdoor models. While installing an outside unit can free up some much-needed floor or wall space, it may be less effective in colder climates due to the water pipes that run outside.

3. Materials

A tankless heating system installation requires a termination vent kit and a gas connector kit, which costs between $20 and $40. The cost of the two-piece brass valve set, mounting hardware and fittings, and other items—which can cost up to $175—is additional. Insulation and any necessary plumbing typically cost $10 per foot.

Why Consider Changing to a Tankless Heating System?

Tankless heating systems can indefinitely produce hot water on demand and are effective in many household and commercial applications. They are also sturdy and reliable. You should always appreciate the significance of correct installation because most of them ought to last for more than a decade.

How Long Does It Take To Install a Tankless Water Heater

Tankless heating systems do away with the installation issue by only using energy when you need hot water and posing a decreased danger of corrosion. Even the bigger units for whole-house use take up less room than conventional water heaters with tanks because there is no bulky tank to worry about.

Additionally, tankless heating systems have features that make installation and use simpler. You should know that the heater’s guarantee can be nullified if a qualified plumber does not install it.

New Technology for Tankless Heating Systems

Tankless technology is always evolving. Here are a few of the most recent improvements:

1. Greater Effectiveness

The second heat exchanger of a condensing gas heater prevents most of the wasted heat from exhausting through the chimney, allowing the heater to recover as much as 96% of the fuel’s original heat.

In addition to costing roughly 25% more than noncondensing heaters, they also produce an acidic condensate that needs to be neutralized. The installation must add a neutralizing cartridge if a heater does not come with one.

2. Instant Hot Water

Even though tankless heating systems only need around 15 seconds to heat water to the desired temperature, the same wait time applies before the water is ready to use in a shower or sink faucet. 

If there are more than 50 feet between the water heater and the fixture, you should seek a model with a built-in recirculation pump. This will help you save water and cut down on your wait time. 

The pump, which may be activated by a smart speaker, a smartphone, a timer, a motion sensor, or a push button, pushes cold water back through the heater. The pump turns off after approximately a minute, and you may turn on the faucet and immediately get hot water.

3. Wi-Fi Compatible

Digitally connected tankless systems allow you to control the temperature and track your hot water and gas usage on your phone. More significantly, the device can locate the origin of a problem.

Your plumber will be able to arrive prepared with such knowledge if you communicate it to them. This feature also gets rid of any hunches about when to descale.

Which Is Better: a Tankless or Tank Water Heater?

The initial installation cost of a tankless heating system is expensive. But these heaters use less energy, which is better for houses or businesses that consume plenty of water. Additionally, they can be covertly deployed so that nobody even notices the presence of the unit.

However, purchasing a tankless heating system is far less expensive. The operation and any necessary maintenance are more straightforward compared to older models. Compared to tank water heaters, tankless heating systems have several advantages.

The tankless heater will save you more money and last 20 to 30 years. That is substantially longer than the service life of tank units, which is just 10 to 12 years.

Additionally, tankless units are compact and take up relatively little space compared to tank units, which require a specific location to stand.

Finally, a tankless heating system that heats water on demand virtually eliminates the need to wait for hot water. The average wait time for hot water to begin flowing from the tap is between 15 and 25 seconds. The tankless unit is a superior choice since its benefits outweigh those of a tankless heater.


We’ve discussed the average time it takes for a licensed professional to install a tankless heating system and some factors that can lengthen or shorten the installation process. 

With this knowledge, you can prepare for your installation time and avoid unpleasant surprises. Additionally, you’ll comprehend the task your professional is doing better.