I want to replace my electric water heater. The current water heater does not have a drain pan. I'd like to add one with my new water heater. This is all in the basement.

Our basement does not have a floor drain. The waste pipe is about 4 feet off the floor. There is a sump pit however, and I'd imagine that's the best place to connect the drain pan to.

How exactly do I do this?

The sump pit is sealed (piece of plywood). I can certainly drill through that, but if I connect PVC from the drain pan to the sump pit then I'm effectively "unsealing" the pit right (air can travel freely from the pit to the drain pan)? I notice the A/C condensation line has a trap built into it, so it's still sealed. Would I need to elevate the drain pan and water heater, and install a trap?

See the picture.


  • 2
    What is the reason you want a drip pan? Eg, do you have a leak, condensation, or is this a pre-emptive thing? (In other words, is there another problem that can be solved that negates the need for this?). Are you willing to dig a trench in your basement floor? Depending on what you're trying to protect from, perhaps a self-contained pan and a water-sensing alarm (flood alarm) would suffice -- it would certainly be a lot cheaper and easier.
    – gregmac
    Jul 31, 2012 at 18:20
  • I don't want to modify the floor. I think it's current county code to have the pan underneath the water heater.
    – jglouie
    Jul 31, 2012 at 19:16
  • If you are going to go through this effort just to comply with code, you should double-check that it is in fact code by calling your local building department. Most of the time as they change requirements, you're grandfathered in so long as you met whatever the code was at time of installation, and it's only when you do alterations (eg, putting in a new heater) that you'd need to comply with new code. Again, check with a local inspector, I'm just some guy on the internet.
    – gregmac
    Jul 31, 2012 at 22:05
  • 2
    Code or not, water heaters do eventually fail -- a relatively small investment in the drain pan may head off a lot of damage if/when the tank fails. When our most recent one failed, it started as a slow seep and we caught it before our basement was flooded. I know of others that were not so lucky.
    – TomG
    Sep 30, 2012 at 1:07
  • I'm with @TomG. An ounce of prevention is worth a pound of cure with anything water-damage related. These things pay for themselves--for less than the cost of one insurance claim deductible you can install quite a few preventative measures, and avoid the headache.
    – STW
    Mar 13, 2014 at 14:09

2 Answers 2


I have a setup similar to yours and the radon installers put a foam sheet over a hole in my sump cover, almost like a thin sheet of packing foam. This is almost airtight but allows some suction for the fan. You could terminate the drain line over a small hole that was covered with foam or paper such that the the air would be sealed in, but in the case you get water from the heater it would drip through it. You could also put a check valve in the pvc line from the heater but it would have to be loose so a trickle of water would trigger it. A trap would dry out, although the HVAC trap probably dries out during the winter anyway....but the suction from the fan should override that small opening.


You could run the drain pipe to the sump pit and install the trap in the pit.The water in the pan would be higher than the trap and flow through it into the sump pit. The problem is that since the pan will only have water in it on rare occassions the water in the trap will evaporate. This will make the pit open to the air via the drainpipe. There are systems designed to remedy this by timing a water release to keep the trap full. I agree with gregmac that this seems like a lot of work for a problem that might not occur. Is it possible that the pan is required but not that it have a hard plumbed drain.

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