Steel Horizontal Vent Kit Zoom

Bosch Stainless Steel Horizontal Vent, 830ES, 940ES Disc

4TWHVK3SII

Status: Arriving Soon

US$458.00

Description

Description

The Bosch Stainless Steel Horizontal Vent Kit, part number 4TWHVK3SII, is a complete sidewall venting kit designed for horizontal exhaust installations on compatible Bosch Therm series tankless gas water heaters. This kit provides all stainless steel venting components necessary to route exhaust gases through an exterior sidewall when the water heater is mounted on the same wall through which the exhaust will be vented. All pipe and fitting components are 3-inch diameter Z-Flex Z-Vent stainless steel, rated for Category II, III, and IV gas appliance venting applications.

The 4TWHVK3SII is the same kit as the AQ3ES designation and is required for all sidewall horizontal venting installations where the heater and the exterior vent wall are the same surface. The kit routes the exhaust horizontally through the wall using the included elbow, pipe sections, and termination components, while combustion air intake is handled separately through a 3-inch PVC or compatible intake pathway that is not included in this kit. A universal appliance adapter and condensate drain pipe, which may be required depending on the specific installation and local code requirements, are also not included.

What's Included: One 3-inch 90-degree elbow, one 12-inch length of 3-inch pipe, one 18-inch length of 3-inch pipe, one 3-inch wall thimble, one 3-inch termination box, and one 3-inch fresh air intake hood. All components are AL29-4C stainless steel Z-Flex Z-Vent construction.

Installation Limits: This kit is intended for installations where the heater is mounted on the same wall through which the exhaust vents horizontally. A 3-inch air intake pipe or hose, a universal appliance adapter, and a condensate drain pipe are not included and may be required to complete the installation. Additional straight vent pipe sections may also be needed depending on the specific installation run length.

Compatibility: Compatible with Bosch Therm 940ES, Bosch Therm 830ES, GWH 715ES, Evolution 500, Bosch AquaStar 2700ES, and Bosch AquaStar 2400ES tankless gas water heaters.

Features

Features

  • Complete stainless steel horizontal sidewall venting kit for compatible Bosch Therm series tankless gas water heaters
  • All components are 3-inch diameter AL29-4C stainless steel Z-Flex Z-Vent, tested and listed for Category II, III, and IV gas appliance venting
  • Includes 90-degree elbow, two pipe sections, wall thimble, termination box, and fresh air intake hood for a full horizontal installation
  • Designed for installations where the heater and the exterior vent wall are the same surface, requiring a horizontal exhaust run
  • Combustion air intake is handled via a separate 3-inch PVC or aluminum flex pipe pathway not included in the kit
  • Also identified by the AQ3ES designation — the 4TWHVK3SII and AQ3ES are the same kit configuration

Specifications

Specifications

Part Number: 4TWHVK3SII
Brand: Bosch
Material: AL29-4C Stainless Steel
Pipe Diameter: 3 inches
Venting Direction: Horizontal Sidewall
Venting Category Rating: Category II, III, and IV
Alternate Designation: AQ3ES
Components Included: 90-degree elbow, 12-inch pipe, 18-inch pipe, wall thimble, termination box, fresh air intake hood

 

The Bosch 4TWHVK3SII Stainless Steel Horizontal Vent Kit delivers a complete, code-rated sidewall venting solution for compatible Bosch Therm series tankless gas water heaters, providing all primary stainless steel exhaust components needed for a horizontal installation where the heater and exterior vent wall share the same surface.

 

Support

Support

 
Product FAQ

What type of installation is the Bosch 4TWHVK3SII horizontal vent kit designed for?

The 4TWHVK3SII is designed for horizontal sidewall venting installations where the water heater is mounted on the same wall through which the exhaust will exit to the exterior. The included elbow, pipe sections, wall thimble, and termination components work together to route exhaust gases horizontally through the wall surface directly behind the heater. This configuration differs from installations where the heater is on a perpendicular wall, which require a different venting kit geometry.

What components are included in the Bosch 4TWHVK3SII vent kit?

The kit includes one 3-inch 90-degree elbow, one 12-inch length of 3-inch pipe, one 18-inch length of 3-inch pipe, one 3-inch wall thimble, one 3-inch termination box, and one 3-inch fresh air intake hood. All components are AL29-4C stainless steel Z-Flex Z-Vent construction. A 3-inch air intake pipe or hose, a universal appliance adapter, and a condensate drain pipe are not included and must be sourced separately depending on installation requirements.

Is the 4TWHVK3SII the same as the AQ3ES vent kit?

Yes. The 4TWHVK3SII and the AQ3ES designations refer to the same horizontal vent kit configuration. Both part numbers identify the identical stainless steel horizontal sidewall venting kit with the same included components and the same compatible heater models. The two designations may be encountered across different distribution channels and product listings but represent the same kit.

How is combustion air intake handled with the 4TWHVK3SII vent kit?

Combustion air intake is handled through a separate 3-inch intake pathway that is not included in the 4TWHVK3SII kit. Commonly used intake options include 3-inch PVC pipe or 3-inch aluminum flex pipe, both of which are available through standard plumbing and HVAC supply channels. Unlike the concentric ESHCK kit, which combines exhaust and intake through a single wall penetration, the 4TWHVK3SII uses separate exhaust and intake pathways requiring two distinct wall openings.

What is the venting category rating for the components in the 4TWHVK3SII kit?

All pipe and fitting components in the 4TWHVK3SII kit are manufactured from AL29-4C stainless steel and are tested and listed to meet Category II, III, and IV gas appliance venting requirements. This rating confirms the components are suitable for the condensing and non-condensing exhaust conditions associated with compatible Bosch Therm series tankless gas water heater installations.

Which Bosch tankless water heater models are compatible with the 4TWHVK3SII horizontal vent kit?

The 4TWHVK3SII horizontal vent kit is compatible with the Bosch Therm 940ES, Bosch Therm 830ES, GWH 715ES, Evolution 500, Bosch AquaStar 2700ES, and Bosch AquaStar 2400ES tankless gas water heaters. Installers should confirm the specific model's venting requirements and local code provisions before proceeding with the installation to ensure all components and configurations meet applicable standards.

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