Thursday, July 12, 2012

backflow preventer question

Do you know know anything about getting a backflow preventer installed?   

What are the expected costs and any suggestions for a plumber / contractor?


  1. The picture above is a backflow valve, but not the one you guys need (it is for supply lines) if you flooded this week. If you had "water" come up through the toilet, tub, drain, etc it was most likely sewage and the device you need is explained in detail here:

    They are basic, and not super expensive, but you need to dig down, find the line and install it (along with an access panel that is large enough to to service and/or replace the device when needed). Just had one installed in my new house last year and it saved me a lot of disgusting mess, BUT be forewarned, this is not a cure-all. Once the valve is engaged, your system is basically locked and therefore cannot accept any other water from any other drain in the house (so if you have exterior drains, you have to have a plan B in place to deal with that water).

    Related side-note:
    With new construction you are only allowed to install this on the waste line that services the basement/ground level (code requires separate servicing). The thought being that there is no way sewage can backflow to 2nd story plumbing and this alleviates pressure buildup in the system (ie. your backflow valve won't double your neighbor's non-equipped system).

    Honestly, DCWater should install these on our homes as a compensation for the thousands we've lost over the years due to their contributory negligence.

  2. Hey Chris, who installed yours? We're looking into it as are Jason and Casey next door and Arli and Sarah on the other side. Afraid of what it might run $$$ with the digging up process though. Thanks for posting this.

  3. Chris: I got the backflow valve pic via Google. So thanks for clarifying what people should be pursuing! Much appreciated.

  4. I would be interested in a rough estimae of cost for the backflow valve also.