Tankless Water Heater close to a window

How Close Can a Tankless Water Heater Be to A Window

Tankless water heaters aren’t quite the latest news in terms of water heating systems, but they’re definitely an impressive opponent to the traditional systems with tanks.

With tankless units being capable of producing hot water only when you need it and where you need it, it’s easy to understand why do they convince more and more customers.

Bells and whistles aside, tankless water heaters do present some shortcomings. They’re not deal-breakers but instead issues to address when it comes to installation. Even if they’re small and compact, allowing storage in narrowest spaces, they still pose some requirements for the mounting place.

Do you plan to use an indoor tankless water heater?

If you intend to install an indoor tankless unit, you should make sure that you provide a 4-ft clearance from the side or below/window that opens. Unless your water heater is vented straight to the outside, you should comply with the specifications.

When your tankless water heater is mounted above a window or a door, you need to allow it 12in of clearance. You’re only going to need 12-in setback from the window/door in the case of direct vent installation. Should the window remain closed at all times, you can give a 12-in setback for the water heater.

Are there any requirements when installing an outdoor model?

We should start by reminding you that outdoor installation is only possible in mild regions, where the temperature doesn’t have freezing values in the winter. If the outdoor installation is possible for you, you need to place the water heater at least 12in away from any door or window that opens. Should you mount it near an inoperable window, the local building codes about the setback vary. Don’t forget that your tankless water heater should have an outdoor vent cap in this case.

Should you pay attention to other aspects?

But it’s not only the windows and door setbacks that you need to worry about when installing your tankless water heater. For instance, you shouldn’t mount the tankless unit close to the dryer vents or intake air vents.

Should you install the tankless water heater between two buildings, you need at least 2ft between the unit and each of the buildings. Moreover, the water heater cannot be mounted straight across from a window or door in the facing walls. If you’re planning to install it above a sidewalk or a paved driveway, make sure you run the measurements, as the unit/or vent need to be 7ft above the ground.

The setbacks we’ve mentioned are minimal, and your local building codes may state more setback requirements. Don’t forget that you cannot just go ahead and install a tankless water heater; you need the building permit before that.

For instance, in California, any water heater has to be anchored, braced, or strapped to the wall studs so that it’s not going to move when an earthquake happens.

Is venting posing any issues for the place of mount?

With gas-fired tankless water heaters requiring venting, it shouldn’t surprise you if you have to check the requirements for the venting. For instance, for an outdoor model, the unit cannot be within an area larger than 4ft below or to the side, one ft above, any operable window or door.

Here are some aspects to pay attention to when finding the best spot for the venting:

  • Tankless water heaters feature fans for blowing exhaust from the unit in a horizontal way, which is why the vents end on the side of your house. You won’t be able to use a current tank vent if it runs from the basement to the roof. More often than not, some drilling will be involved in complying with the requirements.
  • We can talk about two main categories of venting for tankless water heaters: direct vent and power vent. In the case of direct vent, two vent pipes or a concentric pipe with exhaust inside the intake vent is needed for drawing air in from the outside. The power vent will attract indoor air for the combustion, requiring only an exhaust vent. It’s a great option that saves you a buck and gives you more room for the venting.
  • The exhaust vent can be made of metal or PVS, but it depends on the type of unit which one you can use. The metal or stainless steel vent exhaust gets quite hot, and it’s expensive to seal to a wall. It’s not going to work with silicone for sealing the gap. The solution comes from the concentric or the condensing unit, with PVC not heating up and being quite affordable too.
  • You don’t need venting for an outdoor tankless water heater, which is why they’re versatile and allow mount in all sorts of places. Nevertheless, go back to the minimal distance you can have from the window.
  • There should be at least 4ft between the tankless water heater vent and the property line
  • Any new or altered gas piping system has to pass the pressure tests
  • You cannot mount a gas-fired tankless water heater in a bathroom, bedroom, clothes closet or any confined space that gives access to a bathroom or bedroom
  • The air vents have to be placed within the upper and lower 12 in of any enclose

More requirements for the vent instead of a conclusion!

In the case of gas tankless water heaters, the requirements are many due to the exhaust gas:

  • The exhaust vent terminal has to be placed at 3ft above any forced air inlet situated within 10ft.
  • There should be 12in below/horizontally from/above any window, door, or gravity air inlet into a residency. The bottom of the vent terminal has to be installed at 12in above grade (minimal).
  • In some scenarios, the exhaust vent terminal must not be, under any circumstance, installed:
  • Near crawl space vents, soffit vents, or areas where water vapor/condensate may lead to hazard or damage
  • Over public walkways, oven, or regions where wetting of surfaces may condensate
  • In the situations where wetting of elements may condensate or water vapor, altering the pressure regulators, relief valves, and so on.
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