Choosing the right parts for a Takagi tankless water heater installation.


The key to getting the right parts for your tankless water heater is to determine the type of installation you’re going to have. Installation can be vertical or horizontal, sealed combustion or in-room combustion and outdoors.

Since Takagi tankless water heaters (TWH’s) have a small footprint, many of them are installed in small rooms with limited or no supply of fresh air (boiler rooms, closets, etc.). Such conditions would require for fresh air intake to be supplied from outdoors. This type of installation is called Sealed Combustion.

If there’s a constant supply of fresh air in a room where the tankless water heater is installed (i.e. large garage, workshop or basement), there’s no need to convert the intake, as the unit will use the intake air from that room. This type of installation is called In-Room Combustion.

Typically, when unit is mounted on the wall, and the conditions allow, most tankless water heaters are vented through the same wall they are secured on, which means a Horizontal Installation. If the unit is vented through a roof, then it is a Vertical Installation.

Whether running vertical or horizontal pipe runs, the following installation practices should be followed:

  • For Takagi Jr: max. vent pipe run is 35ft, max. amount of elbows is (3);
  • For Takagi T-K3: max. vent pipe run is 50ft, max. amount of elbows is (5);

Outdoors Installation.

Takagi T-K3-OS-NG and Takagi T-K3-OS-LP are outdoor models, and do not require any special venting parts or accessories. All other Takagi models will require the use of category III stainless steel venting parts (Z-Vent by Z-flex or T-Vent by Takagi).

If a model such as Takagi Jr, Takagi T-K3 or Takagi T-K3-SP is installed outdoors, the only part required is the TK-TV04 outdoor vent cap. All other installation types are for indoors only and are described below.

Horizontal Installation, In-Room Combustion.

When installing a Takagi T-KJr-NG, T-KJr-LP, T-K3-NG or T-K3-LP model in a room with an unlimited fresh air supply, direct vent conversion is not needed. For a horizontal installation, where the unit is vented through the same wall it is installed on (typically, right above the unit), a 2ZVWB04 vent kit is sufficient for a 4-7" thick wall.

If penetrating more than 1 wall, get an extra (1) 2SVSTWF04 wall thimble for every 4-7" thick combustible wall.

When installed, 2ZVWB04 kit looks like this:

Vent Kit for Takagi tankless water heater

If venting the Takagi tankless water heater through a wall further away from it, additional 2SVEPWCF0402, 2SVEPWCF0403 or 2SVEPWCF0404 – 2ft, 3ft or 4ft pipes may be needed as well as 2SVEEWCF0490 - 90-degree elbow(s), and/or 2SVEEWCF0445 – 45-degree elbow(s) to make any turns.

Optional:

  1. It is also recommended to install a 2SVEDWCF04 horizontal condensate drain tee and a 2SVEDTK18 condensate drain hose kit for any pipe runs over 5ft.
  2. For remote temperature control and monitoring of Takagi Jr and T-K3-OS models, use a TK-RE02 controller; for Takagi T-K3 models, use a TM-RE30 controller.

Vertical Installation, In-Room Combustion.

When installing a Takagi Jr, Takagi T-K3 or Takagi T-K3-SP in a room with an unlimited fresh air supply, direct vent conversion is not needed.


For a vertical installation, when venting through the roof, the following parts are required:

  1. (1) 2SVSSCSF04 - rain cap with storm collar. If extreme weather conditions exist (wind/rain/storms), this part must be replaced with (1) 2SVSHRC04 - extreme weather rain cap.
  2. (1) 2SVSLSF04 - storm collar & pipe (top) support.
  3. (1) 2SVSADJF04 for pitched roof or (1) 2SVSSCSF04 for flat roof – roof flashing.
  4. (1) 2ZVB04 – appliance adapter with built-in backflow preventer: adapts the Takagi flue outlet to Z-Flex pipes.
  5. 2SVEPWCF0402, 2SVEPWCF0403 or 2SVEPWCF0404 – 2ft, 3ft or 4ft pipes (can be trimmed to a necessary length with a regular hacksaw).
  6. 2SVEEWCF0490 - 90-degree elbow(s), and/or 2SVEEWCF0445 – 45-degree elbow(s) to make any turns.

Optional:

  1. It is also recommended to install a 2SVEVWCF04 vertical condensate drain tee and a 2SVEDTK18 condensate drain kit for all vertical installations. This condensate tee also acts as a 90-degree elbow and eliminates the need for purchase of a separate fitting.
  2. When penetrating a combustible floor or ceiling above the unit, local codes may require appropriate fire protection, such as a 2SVSFSF04 fire stop spacer or 2SVSFSSF04 fire stop support.
  3. To override factory temperature settings and monitor a tankless water heater, use TK-RE02 controller for Takagi Jr and T-K3-OS models; for Takagi T-K3, use a TM-RE30 controller.

Money-saving option:

A 2SVSRPK04 vertical vent kit from Z-Flex contains a rain cap, top (pipe) support and a pitched roof flashing. Part #’s accordingly are 2SVSSCSF04, 2SVSLSF04 and 2SVSADJF04.

Horizontal Installation, Sealed Combustion.

If installing any of the Takagi tankless water heater models in a room with limited or no fresh air supply, the intake air has to be supplied from outdoors. In order to modify the tankless water heater’s air intake system, a direct vent conversion kit must be installed.

This installation method is compatible with the following Takagi models: T-KJr-NG, T-KJr-LP, T-K3-NG, T-K3-LP T-K3-Pro-NG and T-K3-Pro-LP.

For a horizontal, sealed combustion installation, where the unit is vented through the same wall it is installed on (typically, right above it), and the wall thickness is within 5-10", a 2SVSHTC43S concentric vent kit is needed.

A typical installation looks like this:

concentric vent kit for Takagi tankless water heater

Other parts required are:

  1. (1) TK-TV09 - for Takagi Jr or (1) TK-TV10 - for Takagi T-K3, a direct vent conversion kit (will allow to connect a 3" air intake to the unit).
  2. (1) 2ZVB04 – appliance adapter with backflow preventer: adapts the Takagi 4" flue outlet to Z-Vent 4" pipes.
  3. To connect the TWH exhaust to the vent kit, 2SVEPWCF0402, 2SVEPWCF0403 or 2SVEPWCF0404 – 2ft, 3ft or 4ft pipes may be needed as well as 2SVEEWCF0490 - 90-degree elbow(s), and/or 2SVEEWCF0445 – 45-degree elbow(s) to make any turns.
  4. To connect the 3" air intake from the concentric vent kit to the tankless water heater, part# 1TLXXXX03, 3" aluminum duct can be used (sold by foot, cut to order).
  5. (2) 7HS44XX – 3" gear clamps to secure the aluminum duct.

Optional:

  1. It is also recommended to install a 2SVEDWCF04 horizontal condensate drain tee and a 2SVEDTK18 condensate drain kit for horizontal pipe runs over 5ft.
  2. For remote temperature control and monitoring of Takagi Jr and T-K3-OS models, use a TK-RE02 controller; for Takagi T-K3 models, use a TM-RE30 controller.




Vertical Installation, Sealed Combustion.

If installing any of the following Takagi tankless water heater models in a room with limited or no fresh air supply, the intake air has to be supplied from outdoors: T-KJr-NG, T-KJr-LP, T-K3-NG, T-K3-LP, T-K3-SP-NG and T-K3-LP.

In order to modify the tankless water heater’s air intake system, a direct vent conversion kit must be installed (see parts list below for SKU#’s).

The exhaust part of the system typically looks like this:

Vertical vent installation for a Takagi tankless w.h.

For a vertical, sealed combustion installation where the unit is vented through the roof, the following parts are needed:

  1. (1) 2SVSSCSF04 – rain cap with storm collar. If extreme weather conditions exist (wind/rain/storms), this part must be replaced with (1) 2SVSHRC04 – extreme weather rain cap.
  2. (1) 2SVSLSF04 – storm collar/pipe support.
  3. (1) 2SVSADJF04 for pitched roof or (1) 2SVSSCSF04 for flat roof – roof flashing.
  4. (1) 2ZVB04 – appliance adapter with backflow preventer: adapts the Takagi flue outlet to Z-Flex pipes.
  5. 2SVEPWCF0402, 2SVEPWCF0403 or 2SVEPWCF0404 – 2ft, 3ft or 4ft pipes (can be trimmed to a necessary length with a regular hacksaw).
  6. 2SVEEWCF0490 - 90-degree elbow(s), and/or 2SVEEWCF0445 – 45-degree elbow(s) to make any turns.
  7. (1) TK-TV09 - for Takagi Jr or (1) TK-TV10 - for Takagi T-K3, a direct vent conversion kit (will allow to connect a 3" air intake to the unit).
  8. (1) 2FAIGAL03 – 3" fresh air hood.
  9. To connect the 3" air intake from the fresh air hood to the tankless water heater, part# 1TLXXXX03, 3" aluminum duct can be used (sold by foot, cut to order).
  10. (2) 7HS44XX – 3" gear clamps to secure the aluminum duct.

Optional:

  1. It is also recommended to install a 2SVEVWCF04 vertical condensate drain tee and a 2SVEDTK18 condensate drain hose kit for all vertical installations. The condensate tee also acts as a 90-degree elbow and eliminates the need for purchase of a separate fitting.
  2. When penetrating a ceiling above the unit, some local codes normally require appropriate fire protection, such as a 2SVSFSF04 fire stop spacer or 2SVSFSSF04 fire stop support.
  3. To override factory temperature setting and monitor a tankless water heater, use TK-RE02 controller for Takagi Jr and T-K3-OS models; for Takagi T-K3, use a TM-RE30 controller.

Money-saving option:

A 2SVSRPK04 vertical vent kit from Z-Flex contains a rain cap, top (pipe) support and a pitched roof flashing. Part #’s accordingly are 2SVSSCSF04, 2SVSLSF04 and 2SVSADJF04.


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