I'm refinishing my basement and I don't want to place a drain in the floor. But I need a place for the HVAC condensation to drain to, and a place for the water heater pressure relief to drain to.

Option 1, there is a nearby soil stack. I'd like to Tee off of that and add a P-trap, but city says I can't because there's no vent.

Option 2, there is a sump (with a pump) nearby. I'd like to drain to that but the city says no (not an "approved" method whatever that means)


  • If it is an option to add a floor drain near your utilities, I would strongly recommend it. This is always a good thing to have when things go wrong to avoid flooding.
    – cyclops
    Commented Dec 7, 2017 at 21:14
  • I don't see any reason why the sump pit wouldn't work, but the city will have the say I suppose. Ask them what they want?
    – TFK
    Commented Dec 7, 2017 at 21:14

2 Answers 2


In the 2015 International Plumbing Code, R504.6 explains the requirements for hot water heater discharge pipe. It looks like you could install something similar to a clothes washer standpipe as long as the hot water heater discharge terminates less than 6" and more than 2x the pipe diameter above the standpipe. By the way, #6 "not to be trapped" refers to the pipe connected to the hot water heater, not the standpipe or floor drain.

2015 International Plumbing Code Clothes washer standpipe


They make condensate pumps for handling your condensate from your HVAC (Search for condensate pumps). This allows you to run your waste water to an available drain. I suspect that you won't be able to find one large enough to handle worst case full open pressure release from your water heater, but it should be enough to handle the typical trickle that results from a normal over temperature / pressure situation.

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