I have a new electric hybrid water heater that emits condensation from a drain tube (normal) which is a bit different than a traditional electric water heater. Right now I have a bucket under the drain pipe and it drains about 1/2 gallon (+/-) per day.

I need to make the pipe drain outside and the water heater is in the garage right next to the wall, so hopefully this is trivial. Regardless I want to know the proper method to do this. I am going to use 1/2" PVC pipe to drain outside.

I have a 1/2" hammer drill, so i suppose I need a large masonry bit (the size of the outside diameter of the 1/2" pipe) and some kind of silicone to seal around the hole, correct?

Can someone please tell me if this is the proper thinking, or how I should go about drilling a hole through cinder block (do I need to worry about wires or rebar?) and seal it?

1 Answer 1


Your instincts sound right. Be sure the drain tube is slanted downward as it exits. Also be sure the outside end of the tube will not be blocked (by leaves, snow, etc.) and that there is adequate drainage away from the outlet site. The ground should be pitched away from the wall (as in every foundation).

The likelihood of rebar or wiring within the cinderblock is very small. To be certain, go slowly and inspect with a light as the pressure changes in drilling. There are hollow sections in concrete and cinder blocks and you should be aiming for those, rather than the webbing between holes.

Sealing should be done with a weatherproof cualking on both inside and outside.

  • 2
    You will probably also need a masonry Hole Saw to drill a nice round hole. this is a cylindrical bit that attaches to your drill. remember the larger the circumference the more torque required by the drill, so just go nice and slow and apply constant water.
    – Hightower
    Feb 13, 2013 at 8:01
  • Is the weatherproof caulking clear in color by chance? The cable guy once drilled through the side of the house and the sealant around the hole was a clear hard material.
    – atconway
    Feb 13, 2013 at 20:18
  • 1
    @atconway you can purchase caulking in a variety of colors. Some are marked as paintable too.
    – Steven
    Feb 13, 2013 at 21:30
  • I just need to make sure the caulking will stick to stucco and cement and it weatherproof.
    – atconway
    Feb 13, 2013 at 21:33
  • 1
    You can use Duct Seal, to seal around the pipe.
    – Tester101
    Feb 14, 2013 at 12:57

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