Z-Flex Z-Vent Stainless Steel Venting Tips

We stock a HUGE supply of both 3" and 4" Z-Flex Z-Vent Stainless Steel Venting. And, we now carry 5" Stainless Steel Venting! Why Z-Flex products? Simply because they are the best!

Our 3" Z-Flex Z-Vent stainless steel vent pipe mates up directly with the following Bosch Vent Kits:

• Bosch AQ3ES Horizontal Vent Kit (used only with the Bosch 2700ES / 2400ES heaters)
• Bosch ES VVT Vertical Vent Kit (used only with the Bosch 2700ES / 2400ES heaters)
• Bosch AQ3 Horizontal Vent Kit (used only with the Bosch 2400E / 250SX / GWH 635ES heaters)

Bosch requires that either 3" or 4" stainless steel vent pipe (AL29-4C) be used when installing the Bosch AquaStar 2700ES / 2400ES / 2400E / 250SX / GWH 635 ES / GWH 715 ES model heaters. The GWH 345 ESR and GWH 450 ESR heaters require 3" stainless steel vent pipe (AL29-4C).

Using other types of venting with the Bosch 2700ES / 2400ES / 2400E tankless water heaters will void your warranty and put your family's health in serious danger. Many of our Bosch 2700ES / 2400ES / 2400E tankless water heater customers ask us if they can use their existing venting. The answer is always NO. And, the Bosch 2700ES / 2400ES / 2400E tankless water heaters must have their own dedicated venting system.

Most customers use the 3" venting with the Bosch 2700ES / 2400ES / 2400E tankless water heaters. If you choose to use the 4" venting, you will need the 3" to 4" Increaser Z Flex Z Vent SS Venting (2SVSI0304).

The two main reasons to use 4" venting with the Bosch 2700ES / 2400ES / 2400E tankless water heaters is if you already have the 4" venting in place or if you intend to go literally straight up with no elbows (see comments below).

Customers installing non-Bosch tankless water heaters often require 4" stainless steel venting. Many of these customers require our 4" Universal Adaptor: Takagi, Paloma, Rheem, Noritz (2SVSNA04.5) to connect their water heater to the 4" piping system. We also carry the 3" Rheem/Paloma Adaptor (2SVPA03) for connections to certain Rheem and Paloma tankless water heaters.

Some of our customers take great care to measure exactly the distances of their pipe runs. Sometimes they have to come back to us to purchase an additional length of pipe.

Here's a tip: Buy a length of straight run pipe that is a little longer than you need. Each piece of straight run pipe can be cut with a hacksaw. You must leave at least 1.5 inches at the male end of the pipe so that it will snug up with the female gasketed end of the next piece of Z-Flex vent pipe. Any part of the male end of the pipe you cut off must be discarded as it no longer has the gasketed female end.

You do NOT need to purchase gear clamps to connect the stainless steel pipes to each other. Each female end includes a clamp and a sealed gasket to ensure a tight and snug fit. Gear clamps are only needed to secure the intake air hose to the Bosch 2400E collar and again to the intake air termination box.

We do sell the Z-Vent Sealant 3oz Tube (2SILRRTV1O6X), but sealant is NOT needed to connect one piece of Z-Vent pipe to another. The sealant is only needed to help ensure that there is a tight connection between the Top Support / Support Collar and the 3" vent pipe so that rain water does not run down the outside of the 3" vent pipe and into the flashing. Sealant is also needed in certain applications in which the normal connections cannot be made, such as when certain Z-Flex adaptors without gasketed seals are used.

Steve