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jerry8mm's avatar
jerry8mm
Explorer
Sep 19, 2013

Black water and Gray water sensors

I am having trouble installing the Horst Miracle Probes in the gray water and black water holding tanks. I'm trying to install them on a 2002 34' National Sea Breeze motorhome. Here are my problems:

1. The probes are 3/8" and the ones on the motorhome look to be 3/4" or 7/8". Does someone make an adapter? They mentioned drilling a 3/8" hole, but I can't get a drill to the top probe.

2. I can't even find the gray water tank or sensors. Does anyone have any idea where to look?

Any help would be appreciated.

Jerry
  • Jerry, I feel your pain. I bought the same sensors last year, and was determined that I WOULD figure out how to install them. My sensors were permanently mounted, so it was recommended that I drill new holes next to them. The 'rub' was that I couldn't get to them without dropping the tanks. No angle drill would do the trick, so I wound up returning the new sensors. Sure did like the design of them though. I spent 3 days trying to figure out how how I could install them. Sure hope you do figure out something. I sure couldn't.:(
  • Thanks for the reply. I'm going to give up and drill the holes. The top one is the only one I can't get to (except at an angle). I plan to leave it as is, since it doesn't show a faulty reading anyway.

    Of course, all of the above is about the black water tank. I haven't even found the gray water tank and sensors yet.

    Jerry
  • Update. I drilled the holes in the black water tank and put the three bottom sensors in. Now everything is working fine with no false readings.

    Tomorrow I will try to find the gray water tank and sensors.

    Jerry
  • As soon as I read this about these sensors I ordered them today and will have them delivered to campground host. I also will have to drill holes.
  • Below is a response I just received from the Horst company. (They also included some links to YouTube videos.)

    I am not familiar with your motorhome but it sounds like your sensors are spin welded in place and they can not be removed. The only way out is to drill 3/8" dia. holes on the same level somewhere around the vertical walls of the tank. The negative probe should be approx. 10" away from the lowest ( usually 1/3 full) probe. Harbor Freight sells a small 90* gear drive for a very low price which may be helpful to get to places. Many customers have used it.
    To find the location of the gray tank, listen to the sound while letting the faucet run in the kitchen.