# How to to remove waste water sensor on Burstner 747



## finyar

Hi there,
I have a problem with the waste water reading in my Burstner 747 (2005). The alarm keeps going off telling me to empty the tank even when the tank is only 25% full.

The levels in the tank are also varying a bit

I have tried resetting the tank alarm but it seems to make no difference and at this stage I have disconnected the sensor.

Has anyone any advice on 

(1) Fixing the alarm

(2) Removing the old sensor from the tank

Thanks
Raymond


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## Pat-H

It maynot be the same but our swift waste tank sensor regularly gives incorrect readings and when I remove it it's covered in grease and muck. A clean and flush of the tank sorts it for a good few months.


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## stewartwebr

Yes agree with Pat-H no matter what make of van I have always been able to resolve the issue with giving the waste tank a good flush out.

There are lots of different products on the market to assist in cleaning the tank and many others will have their own methods.

The one that has always worked for me is fill the tank with warm water (not too hot) and as you run the water in add a large amount of BIO washing powder. Give it a few hours to soak in, give the van a good run to swash around then empty it out. Always seems to resolve the issue. 

You can also unscrew the inspection cap on the Burstner and give the probes a wipe...just make sure the tank is empty before unscrewing the inspection cap :roll: 

Stewart


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## finyar

Thanks for the replies.
I will try the tip with the warm water and washing powder, I have already opened the tank and cleaned the rods with a piece of kitchen towel but to no avail.

The problem is that I can't physically see the sensor so have no idea if I have managed to clean it or not

Thanks
Raymond


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## finyar

*Urgent help needed*

Hi all, 
I need help

I cleaned out both waste and fresh water tanks as suggested and now both tanks are giving incorrect readings.
It is almost as if the probes need to be calibrated.

Obviosly I have done all the normal checks, reset the complete system, disconnected both probes from their connection ( this then shows zero, until you reconnect)

Starting to loose patience with it at this stage.

Any advice , most welcome


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## 747

Remove the probes completely and thoroughly clean. Use white vinegar or an abrasive scourer that your wife might have for cleaning pots and pans etc. That cured mine.


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## finyar

747, 
Thanks for the advice on the vinegar, have you any ideas on how to remove the probes. There is a nut on the inside of the probe ( in side the tank,which I cannot see!) and its more than hand tight.

Raymond


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## 747

finyar said:


> 747,
> Thanks for the advice on the vinegar, have you any ideas on how to remove the probes. There is a nut on the inside of the probe ( in side the tank,which I cannot see!) and its more than hand tight.
> 
> Raymond


I used adjustable pipe grips. The big plastic nut is not a lot more than hand tight and loosens fairly readily.

If you wrap a piece of cloth around the external part of the probe and put your weight behind it, you might manage without the pipe grips. Remember to hold the nut while you do it.


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## finyar

Went into the van this morning and the probes were reading correctly so I have decided to leave it alone until they mis-behave again.

Thanks for all you help

Raymond


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## Bagshanty

The system uses the conductance of the liquid, the same as for fresh water. Pure water does not conduct much at all (in Norway some time ago our fresh water showed 0% even though the tank was overflowing). So it depends on the impurities in the water/waste. Lots of impurities = lots of conductance. I ignore the waste tank readings, they will always be unreliable (but it is annoying to get the "full" alarm beeping when it isn't)


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## inkey-2008

When you clean the probes make sure you clean right to the top and the head as you can push derbies to the top out of sight and will continue to give false readings.

Andy


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## finyar

All,
I eventually removed the sensor today, the nut, is a 32 if that's of use to anyone else. I cleaned the rods with wet and dry sandpaper and was suprised how coated they were.

The good news is that I think I have solved the problem.

Thanks for all the help

Raymond


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