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Condensate Line on Tankless Water Heater


Sep 10, 2010
PA/NJ - Borderlands
So I have a question on a where a condensate line is allowed to drain.

A little background the building is at a private outdoors club and the mechanical room is on one side of the building and 40 feet away are the 2 bathrooms & 1 slope sink.

Thus, you have a total of (3) sinks being feed off the water heater and the 2 bathroom sinks are using motion sensor faucets (Bought 2nd hand) as thus I am not even sure hot water is going to make it to them for the amount of use they will get, for this limited use building.

ITs a pole barn, so concrete floor with a metal ceiling and blown insulation.

Based on the manual the limited amount of water it will produce won't even keep a trap filled.

We are estimating 1 cup of water about every week during the winter when the building is in use and June through September maybe 2 cups in total over the 4 months.

The 5" concrete slab sits on 8 inches of gravel covering over 800 square feet minimum, and the unit has a built in neutralizer, so the water is treated.

To run it out the side of the building will ultimately freeze and we are wondering if something like this can just be core drilled through the slab and caulked?
@ ~ @ ~ @

tbz, ...the Mechanical Code allows the condensate drain
to terminate at "an approved location"..........To keep
the P-Trap from drying out from lack of regular use,
fill it with mineral oil..............It will keep the trap sealed
for a long time & it's environmentally friendly.

With the lack of regular use, you could have some type of
indoor container located to where someone could easily
notice when it is time to empty it, during the warmer
times of the year.........Then during the winter the line
won't be exposed to colder temperatures and freeze.

@ ~ @ ~ @
We do not accept condensate draining below a slab.
There’s several municipalities that will not permit draining to a trap as it is unmetered water into the sewer system, not just a neutralizer concern. Some municipalities in Pa relate this to an I&I (inflow & infiltration) issue.
What about draining to the exterior, if concerned about freezing place heat tape and black split foam pipe wrap or similar.
Thanks everyone,

I will let them know they can drain to outside the building wall easily, the HVAC contractor does not want to,

5ft across the interior wall, through the side of the building and downward facing.

just going to use everyone's suggestions with the oil and through the wall and call it a day.

Keystone, they are on well and septic, so no municipal sewer system to deal with
We see a few floor mounted mop sinks here with the a demand WH above which has the PRV drain terminating in the mop sink, is that an option even with a standar WH?