The Bosch 2700ES / 2400ES Installation Manuals states that the Bosch 2700ES / 2400ES tankless water heaters requires the installation of an external condensate drain for:
- ALL vertically terminating vent installations;
- All Horizontal terminating vent installations where the total vent length is greater than 10 feet; or
- Vent installations where any section of the exhaust vent pipe passes through an unconditioned space
There are three 3" Z-Flex Z-Vent condensation drain parts that you can choose from:
- 3" Vertical Condensation Drain Tee (2SVEVWCF03)
- 3" Horizontal Condensation Drain Pipe (2SVEDWCF03)
- 3" Vertical Condensation Drainpipe (2SVEVDP03)
Each of these will require a Condensate Drain Kit (2SVEDTK24).
If you must go straight up from the Bosch 2700ES / 2400ES / 2400E heaters, we recommend that you use the 3" to 4" Increaser (2SVSI0304) and then run 4" Z-Flex Z-Vent venting. This will allow you to use the larger 4" Vertical Condensation Drainpipe (2SVEVDP04). This 4" drainpipe has a much higher capacity for removing condensation and rain than does the 3" drainpipe.