Holding Tank Sensor

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

Ray

Veteran Member
Joined
Nov 27, 2011
Messages
70
Location
USA
Vessel Name
PatsyRay
Vessel Make
2004 Mainship Trawler
Our holding tank sensor/gauge does not work. The light on the gauge is on showing it is getting 12 volts, it is easy access to the sending unit, can these be cleaned or buy new?

Thanks Ray
 
What is the make of the sensor? If it's a Tank Watch 4, yes the floats and the rods they are on can be cleaned. Can be a bit of a nasty job :eek:. Or you can buy a replacement. But eventually the floats will crud up again.

Or you can do yourself a big favor and buy a SOLO sensor and panel (external or internal based upon your holding tank material). Uses the same wiring as the Tank Watch.

If you have a different make, post it and someone will chime in.

Or it could just be a problem with the wiring. Check the continuity of each wire between the sender and the panel.
 
if it has floats they dry out. Using the boat often frees them up or fill the tank and go for a ride.
 
Or you can do yourself a big favor and buy a SOLO sensor and panel (external or internal based upon your holding tank material). Uses the same wiring as the Tank Watch.

I totally agree! However, "Solo" isn't a brand name, it's the single tank model of the Profile system. Profile Tank Monitors The senders are attached to the outside of the tank, so can never become clogged by the animal fats in waste, and--as dwatty noted--can use the same wiring as the TankWatch, which makes 'em a piece o' cake to install.
 
Thanks for the replies, it is a Wema SHS which is standard equipment on the newer Mainships. It appears to be a tube with maybe a float inside? Have not taken it out of the tank yet, just looking at the web site. They have no information about cleaning or maintenance


Thanks Ray
 
Hi Peggy,

Is there any special wiring that needs to change when using this sensor with an existing tank watch monitor?
 
The wiring for both the Wema and the TankWatch system will work with the Profile system...and also the Snake River systems.

And Dennis Ferriello will give you all the help you need to install it. He's the only vendor I've ever known who'll even answer the phone on a Sunday afternoon.
 
Peggy


Who is Dennis Ferriello ? Phone # please.


Thanks Ray
 
Or you can do yourself a big favor and buy a SOLO sensor and panel (external or internal based upon your holding tank material). Uses the same wiring as the Tank Watch.
I couldn't agree more! Over the years (since 1995) I've tried all the holding tank monitors and Solo, is by far the best! No maintenance, no components inside the tank, truly a DIY project. (Super easy!) and a low price, compared to everything else that's on the market.

http://www.defender.com/product.jsp?path=-1|51|2234305|2234306&id=1249539
 
Last edited:
Just for clarification one more time (which seems to be a good idea today)...the SOLO isn't a brand name, it's the name for the single tank model of the Profile gauges...and also the single tank model of the SCAD system. SCAD is a private label brand name for the Profile gauges.
 
Thanks for the replies, it is a Wema SHS which is standard equipment on the newer Mainships. It appears to be a tube with maybe a float inside? Have not taken it out of the tank yet, just looking at the web site. They have no information about cleaning or maintenance


OK, I've got this one. :)

The WEMA SHS is a stainless (I think) float within a stainless tube, and it works on resistance (high resistance = float low = empty; low resistance, float, high = full).

First, put a multi-meter on it to confirm you've got continuity. You probably will.

If so, pump out and rinse a few times, ending on a pump-out... and then remove the sensor. You'll likely find it covered with crystalline uric scale (or whatever it's called; Peggie will know) and that's what's keeping the float from moving.

Soak the whole tube in a light solution of muriatic acid or some such (vinegar didn't work) to free up the float and clear out the tube, and afterwards recheck continuity, re-install if good.

Actually replacing the sensor is easy, too, but when I replaced out sensor at the end of last season I was able to clean up the previous one and save it back as a spare. (That previous SHS was a replacement for the earlier original, and that original had a plastic float. The newer stainless models seem to work much better.)

Once you're reinserted the sensor and while you still have visual access to the tank, you'll probably benefit by taking a moment (or three) to determine your real holding tank capacity... and then mark the place on the WEMA gauge (display) that REALLY means FULL (or "pump soon" or whatever you like). We found our nominally 40-gallon tank actually only gives us about 24 gallons real capacity... owing to the wall thickness, inlet and vent hose locations, etc.

-Chris
 
Last edited:
WEMA gauges are standard on a lot of production boats 'cuz they're inexpensive. They're fine for water and fuel, but have always had a high failure rate in waste tanks because the the animal fats in waste, along with sea water minerals and urine crystals--the latter more common in tanks fed by toilets that use very little flush water--clog up the sender (same with the TankWatch and any other senders that are immersed in the contents). Removing 'em to clean 'em manually is the only way to clean 'em.

Before I'd do that, I'd replace the sender with the Profile "solo" sender. It goes on the outside of the tank and can use the existing Wema wiring. The Profile system also has a sender for metal tanks that goes inside the tank, but it's encased in a pvc tube, so it never comes in contact with the contents either.

Btw, Chris...vinegar does work to clean scale off senders and inside hoses, but it's such a long and tedious process that requires changing the vinegar frequently (which you prob'ly didn't know to do) that it's not worth the effort. Much easier to use muriatic acid or Sew Clean and use distilled white vinegar to PREVENT buildup in hoses.
 
WEMA gauges are standard on a lot of production boats 'cuz they're inexpensive. They're fine for water and fuel, but have always had a high failure rate in waste tanks because the the animal fats in waste, along with sea water minerals and urine crystals--the latter more common in tanks fed by toilets that use very little flush water--clog up the sender (same with the TankWatch and any other senders that are immersed in the contents). Removing 'em to clean 'em manually is the only way to clean 'em.

Btw, Chris...vinegar does work to clean scale off senders and inside hoses, but it's such a long and tedious process that requires changing the vinegar frequently (which you prob'ly didn't know to do) that it's not worth the effort. Much easier to use muriatic acid or Sew Clean and use distilled white vinegar to PREVENT buildup in hoses.


Yep, you're right, I didn't know that. I gave the first batch of straight vinegar 24 hours, and it didn't look like it was gonna do squat... so I escalated right away. :)

FWIW, I put that earlier SHS in there at the beginning of our 2007 season. It started getting balky toward the end of the 2014 season... then mostly was a pain in the neck during 2015 until I finally replaced it. Not all that bad a track record, in the grand scheme of things. This is on a holding tank fed by an electric freshwater macerating head, and we use plenty o' water usually.

Had I just taken it out and cleaned it in mid-2014 when it first started acting up, that probably would have been OK too.

-Chris
 
Our holding tank sensor/gauge does not work. The light on the gauge is on showing it is getting 12 volts, it is easy access to the sending unit, can these be cleaned or buy new?

Thanks Ray


Ray, if it's a slider / floater then it can be cleaned, I've done it a few times. If it's a non contact proximity type then I think you're S.O. L .... pardon the pun ... :)
 
Thanks for all the good information, I took the sending unit out of the tank and soaked it in a bucket of "The Works " toilet bowl cleaner from the dollar store. Thirty minutes later with a blast of water from the hose nozzle the float inside the tube was sliding free, put it back in the tank and the gauge worked. I remember Peggie suggesting the use of Odorless tank treatment, which I just ordered. One more boat problem solved, with many to go.


Thanks Ray
 
OK. I purchased the SCAD Solo. Installation instructions are well written and seem pretty straight forward. Except to calibrate the FULL tank, they say to avoid calibrating with fresh water, if possible. Waiting for the holding tank to unexpectedly fill to the brim is not an ideal situation, for many reasons. Has anyone calibrated with fresh water? Or perhaps put some dark food coloring or something else??
 
I'm not sure why they'd recommend against using fresh water, since a lot of toilets use fresh water. So I suggest you ask the mfr, which isn't SCAD...it's just a private label brand name for the Profile tank monitors Profile Tank Monitors . One of the reasons Practical Sailor rated SCAD the #1 tank level monitors is their outstanding customer service...not realizing that when you call them for help, your call actually goes to Dennis Ferriello, the mfr. So I suggest you give him a call directly: 435.656.0042
 
Given that it's 2016, I would strongly suggest against getting any tank level reporting product that doesn't have an NMEA 2000 or Signal K interface. It's sort of like getting a Loran in 1995. Get something that can warn you and interface to other capabilities - you'll be using it in 2020.

It doesn't appear like Profile, SCAD, SOLO, or whoever is making this and/or putting their name on it has any type of normal interface. At a minimum, ask them if it can be added. It should be part of the system and if enough people ask, maybe they'll add it.

Just my $0.02. Most people will likely disagree. Come back in 2020 and see if I was right...
 
Given that it's 2016, I would strongly suggest against getting any tank level reporting product that doesn't have an NMEA 2000 or Signal K interface. It's sort of like getting a Loran in 1995. Get something that can warn you and interface to other capabilities - you'll be using it in 2020.

It doesn't appear like Profile, SCAD, SOLO, or whoever is making this and/or putting their name on it has any type of normal interface. At a minimum, ask them if it can be added. It should be part of the system and if enough people ask, maybe they'll add it.

Just my $0.02. Most people will likely disagree. Come back in 2020 and see if I was right...


It's a reasonable path forward... but OTOH, if there's no easy way to get the signal from sensor to display... it's difficult to raise this as a priority in existing systems.

I could run a wire. Pain in the neck. (Not sure my plotter supports a way to display that particular kind of data, even though it's a NMEA2000 unit.)

I could get some kind of wireless interface. If my plotter can now physically accept one. and solve the display (It won't, I think.)

I could buy a new display, with a wireless interface. Or I could buy and add a wireless interface to the network for the new display. Pain in the neck.

Of I could simply resign myself to using the existing display (gauge). OK, it's a Loran-equivalent, but it's cheap. Fast. No pain.

Makes a lot of sense to adopt a systems approach -- using the latest and greatest -- if there's lots of change going on, but... for one lousy piece of data... in an existing system of various age... there's a practical limit to how much work/$$$ is helpful.

-Chris
 
I'm a lover of modern technology and have all of my instruments connected to NMEA2000 in order to share data. But my tank level display is in the forward head, its easy and normal to see it "regularly". I don't really see the need to be able to monitor the holding tank level from my chart plotter?

Ken
 
Do you think that's really necessary for a device on which the sensors use capacitance to read through the tank wall, only draws milliamps, and only reports 1/4, 1/2, 3/4 and FULL?

As for SCAD'S advice not to use fresh water, they should have advised against using DISTILLED or filtered water, 'cuz every liquid has a dialectic value. Pure distilled water with no impurities has a value of 0 so the sensors can't read it.

Btw, "SOLO" isn't a brand name...it's just the name for the single tank version of the SCAD/Profile gauges. They also offer systems that can read up to 8 tanks.
 
I calibrated my "FULL" mark by filling up the tank with fresh water. I removed the cover that held the Tank Watch tubes and had a friend tell me when the water level was at the top of the tank. I then re attached the cover, did the "Full" calibration as per the instructions and everything worked fine! Just returned from a 140 mile cruise with 4 adults aboard, (4 days) and the tank monitor read ¾ full. (3 green lights) This is a great tank monitor! :dance:
 

Attachments

  • FullSizeRender-1.jpg
    FullSizeRender-1.jpg
    131.4 KB · Views: 79
I calibrated my "FULL" mark by filling up the tank with fresh water. I removed the cover that held the Tank Watch tubes and had a friend tell me when the water level was at the top of the tank. I then re attached the cover, did the "Full" calibration as per the instructions and everything worked fine! Just returned from a 140 mile cruise with 4 adults aboard, (4 days) and the tank monitor read ¾ full. (3 green lights) This is a great tank monitor! :dance:

Walt: What's the size of your holding tank on your new boat?
 
Wow, the SCAD is less than half the price of the Gobius system (the only other similar system I was aware of - until now!). I think we'll be getting the SCAD soon...

Gobius waste holding tank level system.
 
Jeff,
Can you recommend a sensor that does work with NMEA2000? I have tried the Maretron TLM100 without much success in getting them to calibrate.
 
Jeff,
Can you recommend a sensor that does work with NMEA2000? I have tried the Maretron TLM100 without much success in getting them to calibrate.
Have you contacted Maretron?

I think their products are pretty good. There are sure to be other, less expensive ones coming out for Signal K too.
 

Latest posts

Back
Top Bottom