monitoring waste water tanks

hrgermany · Post by **hrgermany** » Wed Aug 26, 2009 8:16 pm

I could newer rely on the reading of the waste water monitoring. Many times I got wrong readings when there was nothing in the tanks. I used chemicals to clean the tank, but not much help. Now I found the solution. I installed in each tank Horst Miracle Probes. That seems to solve the problem. The old ones consists only of a stainless screw were the head sticks into the tank. The new probes are about 2 inches long. The sensors for the black tank have a half cover over the top.

The easy way is just to drill new 3/8 holes next to the old ones. But I went the long way and removed the old sensors (screws).

The company that make those does not sell direct. I got mine from probes@rv probes.com. Tel 303-351-4506. Cost $70.70 including shipping. They are nice people to deal with.

Hans Rueckert
1995 BF 26 RSB

Mike Astley · Post by **Mike Astley** » Thu Aug 27, 2009 12:21 am

Did you have trouble removing the old sensors? I ask as I bought a set of the Horst sensors for the black tank and when I tried to remove the first sensor it wouldn't come out.

I asked Kim in customer support about it and he said trying to remove the old ones could damage the tank, just drill new holes.

hrgermany · Post by **hrgermany** » Thu Aug 27, 2009 1:22 am

Yes it was a little hard to remove the old sensors. You have to leave a nut and the washer on the old sensor, move the sensor back and forth and apply a little pressure and the old sensor will come out. The tank is thicker than I thought.

Hans rueckert

Ray'n Mary · Post by **Ray'n Mary** » Sat Aug 29, 2009 12:28 am

I've had the same problem, and appreciate your finding and posting a solution.
Question: Do the new probe(s) connect to the readout panel above the stove, through the same wiring as the old ones?

hrgermany · Post by **hrgermany** » Sat Aug 29, 2009 12:37 am

Yes they do. Connect the same colored wire at their same sensor position.

Hans Rueckert

David and Susan Bratt · Sat Aug 29, 2009 12:37 pm

This has me wondering.... If you can take out the old sensors to replace them, can you take them out and clean them off and simply put them back in?

bcope01 · Post by **bcope01** » Sat Aug 29, 2009 1:06 pm

David and Susan Bratt wrote:This has me wondering.... If you can take out the old sensors to replace them, can you take them out and clean them off and simply put them back in?

You probably can, but it may be the conductive sludge on the inside tank wall as much as it is fouled sensors. It is not a lack of electrical contact to the sensor that gives a false reading, but just the opposite, i.e., electrical contact where there shouldn't be. So, cleaning the sensors themselves would only be a short-term fix at best, IMHO.

Bill

Mike Astley · Post by **Mike Astley** » Sun Aug 30, 2009 11:08 am

hrgermany wrote:Yes it was a little hard to remove the old sensors. You have to leave a nut and the washer on the old sensor, move the sensor back and forth and apply a little pressure and the old sensor will come out. The tank is thicker than I thought.

I went back and tried to remove a sensor again but without success. I believe I will need to drill new holes. Unfortunately the top sensor (full tank sensor) is too close to a cross beam to allow drilling so will have to leave the old sensor in.

Dallas Baillio · Post by **Dallas Baillio** » Sun Aug 30, 2009 8:50 pm

I have no real interest in this discussion since I don't consider the inaccuracy a major problem, but here is a link to installation of an outside the tank device on a Lazy Daze MH.

http://www.andybaird.com/travels/skylar ... gauges.htm

bcope01 · Post by **bcope01** » Sun Aug 30, 2009 11:52 pm

Mike Astley wrote:Unfortunately the top sensor (full tank sensor) is too close to a cross beam to allow drilling so will have to leave the old sensor in.

Mike, would one of these 90 degree swivel drill chuck attachments help you get that top sensor hole drilled? I own one and have used it often. Costs $15 (on sale often for less) from Harbor Freight: http://www.harborfreight.com/cpi/ctaf/d ... mber=92188

Bill

Mike Astley · Post by **Mike Astley** » Tue Sep 01, 2009 9:57 am

Nice suggestion! I didn't know such a widget existed. I'll check into it and see if it provides enough clearance. Thanks!

Mike Astley · Post by **Mike Astley** » Sun Sep 20, 2009 8:46 am

Thought I'd post an update to my project of installing the new sensors. I did end up drilling new holes as I could make no progress removing the old sensors. I had to use the right angle drill attachment from Harbor Freight that Bill suggested to even be able to drill the lower three sensor holes. The clearance for the top sensor is just too tight to the steel frame to be able to do anything with, so I left the old, topmost sensor in.

As I filled the black tank, the sensors all worked in expected order and the readout dropped back to empty when the tank was drained. And no leaks from either the new sensors or the old ones that I wrestled with trying to remove. So, success!

There are often "points of no return" on projects, and I had to calm my nerves a lot each time before drilling a hole into the black tank!

FYI, I did consider, earlier, the SeeLevel monitor that Dallas provided a link to. I love digital gauges vs. idiot lights! But in reading the installation instructions on their web site, they require a minimum clearance from other objects and the steel beam on my coach disqualified my RV.

I only did the black tank as I haven't had any problems with the grey tank display, and, in our usage, the black tank always fills up first.

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