Fresh water tank gauge

[petem]

I know this topic has come up before but my freshwater tank gauge is giving an incorrect reading. This is the sender...

Having looked at previous threads I was expecting the sender to be some kind of arm or pressure detecting device. However, as you can see the sender consists of a rod with a float (a magnet perhaps?) that slides up and down with the water level. When empty the gauge is reading 3/4 full and when full it reads full.

Any idea that the problem might be?

 

[jimmy_the_builder]

Probably a duff sender, the way to check this is to measure the resistance as you move the float up and down the rod. Looks like a Wema sender.

 

[Nick_H]

Yep, it's a Wema sender. I've had success before by cleaning the sender thoroughly with soapy water, even when it already appeared clean. Probably worth a try before ordering a new one.

 

[Phildorset]

If it can't be fixed and you can't get a replacement then I can vouch for the Gobious gauges - I've had them installed on my black water tank, the sensors stick on the outside of the tank... mine came from TekTanks, no connection - just a happy customer with a reliable tank level gauge

 

[petem]

Yep, it's a Wema sender. I've had success before by cleaning the sender thoroughly with soapy water, even when it already appeared clean. Probably worth a try before ordering a new one.

Nick, what would you clean? All it is is a smooth shaft with all the gubbins on the inside (sealed)?

 

[Nick_H]

Nick, what would you clean? All it is is a smooth shaft with all the gubbins on the inside (sealed)?

The outside of the shaft and the float. It makes no sense as they appear clean already but it worked for me. It's possible of course that it was the wiggling around rather than the cleaning that fixed it, but either way it's worth a try.

 

[stelican]

You need a new sender

 

[MrB]

Cheap enough fix. http://www.force4.co.uk/wema-stainless-steel-fuel-water-sender-m.html#.WbXAwtR97cs

 

[vas]

I know this topic has come up before but my freshwater tank gauge is giving an incorrect reading. This is the sender...

Having looked at previous threads I was expecting the sender to be some kind of arm or pressure detecting device. However, as you can see the sender consists of a rod with a float (a magnet perhaps?) that slides up and down with the water level. When empty the gauge is reading 3/4 full and when full it reads full.

Any idea that the problem might be?

Pete,

do you get these values when you slide the floaty thing up and down? I mean if you slide the float all the way to empty (with sender as it is outside the tank) and you still get 3/4 full, just get a new sender...

V.

 

[petem]

Pete,

do you get these values when you slide the floaty thing up and down? I mean if you slide the float all the way to empty (with sender as it is outside the tank) and you still get 3/4 full, just get a new sender...

V.

Yep, we tested it off the tank by moving the float up and down and these were the readings we saw. Consensus seems to be that it's the sender not the guage so will order a new one. Given more time I'd measure the resistance but getting short of time now.

 

[vas]

Yep, we tested it off the tank by moving the float up and down and these were the readings we saw. Consensus seems to be that it's the sender not the guage so will order a new one. Given more time I'd measure the resistance but getting short of time now.

unless PO replaced the WEMA sender with a wrong type one, but I doubt it would be like that, probably inverse as well.

cheers

V.

 

[jimmy_the_builder]

Yep, we tested it off the tank by moving the float up and down and these were the readings we saw. Consensus seems to be that it's the sender not the guage so will order a new one. Given more time I'd measure the resistance but getting short of time now.

Remember this isn't something that you need to fix before the boat goes on transport - you can take a replacement sender in your hand luggage if necessary. You probably *do* need to check the resistance on the sender though, because there are two resistance standards for these senders. Also, you may find that the sender is not a standard size - Wema custom-made senders for Fairline; when one of mine failed, I had to get one direct from Wema made to the correct size.

 

[Portofino]

Interestingly ,I've just gone through all this --water sender .
With VDO , there two types ,resistance and capacitance ,sods law ( never for away when fixing boats ) I ended up fitting the wrong one .
I bought a wema suposed replacement from ASAP in the post and carted it to the boat .£60
It came with a fitting kit -various ring adaptors , but when I wired it up it did not work .
The OEM VDO was € 260 mail order ,and thought I was being clever going down the wema route !

Having dismantled the stairs to gain access in sodding 30 deg heat I went to the local chandler in the marina , who looked up in a catalog the OEM part I had in my hand ---€ 140 , ordered it came ( txt me ) later that afternoon .
It was a capacitance type --fitted --bingo .
I think the one I bought from the tinternet will fit the black tank ,so its a spare , well that what I told the wife .

Moral of the story is buy local --- you gonna get v friendly with the marina shop anyhow .

Why there's not an industry standard I don,t know ?

 

[Fredd]

On my last boat i replaced the senders in the water and fuel tanks with these https://osukl.com/tanks/
I found them to be excellent , very accurate and with the nmea 2000 just plug and play and displayed on the MFD . Its about 7 years ago now so i dont know what the prices are like now but i felt they were good value at the time .