Do the ultrasonic level meters ever go wrong?

quartzz · 3 February at 2:20PM

I moved into this property in Oct 24 - the LCD level meter was at 80%. I've checked every week or so, the LCD bar level meter hasn't changed-which I was pleased about. I've just stuck a twig into the ultrasonic hole access in the tank (I wanted to swirl the water (oil) to get some heating oil cleaner additive mixed up), and the twig appears to move around very freely with a "this does not feel like liquid" to it. Can the ultrasonic level sensors go wrong?

wwally · 3 February at 10:59PM

Use the twig as a dipstick and measure the depth of oil. There are calculators online that convert depth into litres for various cylindrical shapes. The rate of fall speeds up drastically as the level falls. I usually order with about 12 inches remaining.

PS. I don't have a monitor - always seemed too expensive and I wouldn't trust it anyway.

quartzz · 4 February at 3:19AM

I mean the U/S meter was there when I moved in, I'll need to find a twig long and thin enough. It can't be more than about 15mm wide, and needs to be about 1.5 m long. the actual access point where the oil goes in has a spherical ball valve that prevents anything from going into the tank ("which is possibly what it's designed to do")

QrizB · 4 February at 7:29AM

Rather than a twig (which might shed bark flakes into your oil) how about a bamboo cane? Or you could buy a length of dowel from one of the DIY sheds?

quartzz · 4 February at 1:12PM

Sure. There are a number of options in the longer term, I was just seeking some information in this instance. an old snooker cue might do the job

Rodders53 · 4 February at 3:37PM

Pics of this tank, please.

Mine has a large port to see the oil level and dipstick it. The ultrasonic device has a separate hole. Bunded plastic.

Our tankers always fill via the port rather than the smaller official screw filler port with a float cut-off.

Beware of stirring up any water that is in the bottom that the oil floats on... getting some into a boiler is usually death to the oil pump.

lohr500 · 4 February at 5:05PM

Yes, they can go wrong. And it sounds like yours has if the level hasn't changed since October and you have had the boiler running for any length of time.

Is yours the version with a plug in display in the house and an LCD display on the tank unit?
If so, do both displays match? Or just a unit on the tank, or a unit on the tank with no display, but with a plug in display in the house?

Regardless of this, remove the sensor unit (if it is a plastic tank, the sensor is probably held in place by two pozidrive type self tapping screws holding it to the tank) and check for any white residue around the sensor area.

If there is no sign of contamination around the sensor, it might be the battery that is failing in the sensor unit.

Ours was made by Apollo and could be dismantled. From memory there is a CR2032 type button battery inside it.
It had a stuck on paper tamper proof seal covering one of the small screws holding it together, but if it isn't working, you have nothing to lose by taking it apart!!

dunstonh · 4 February at 5:36PM

My apollo meter failed last year. It was stuck on the same bar and I was getting suspicious. I use a broom handle with markings on it to indicate the levels and it was going down and the meter had failed.

A battery didn't fix it and I had cleared the white residue. So, It was a new unit for me.

quartzz · 4 February at 5:50PM

I'll get some or all of these details tomorrow, thanks

Rodders - that's actually quite interesting. as well as the sphere-valve hole for the oil and the 15mm one for the ultrasonic, there's a third smaller vertical compartment which looks like it has transparent liquid (water?) and a mirror at the bottom - I was going to post about this asking what it is. I can see my reflection clearly in the mirror - I was assuming this was a good thing and that it was free from contaminants....but......?

when I moved in I did try bringing the ultrasonic into the kitchen to see if the LCD would change-- it did. the sensor (the sensor housing) is a round grey thing that looks a bit like a tall UFO, 4 inches diameter, no electronics on the tank that I've seen, the LCD bar meter is on the little wall plug in thing. the LCD display gadget doesn't seem to remember the level (or the ultrasonic comms link doesn't hold up -- etc), so I leave it unplugged, plug it in and wait 2 minutes when I want a reading.

the sensor housing does have (philips) screws, but there's a "warranty void if removed" sticker over one of them. come to think of it, I doubt it's in warranty. Tank is a Deso SL650BT

quartzz · 5 February at 1:39PM

right. no photo's yet (will get if preferred) I've just brought the U/S sensor indoors, and the LCD is still at 80% 8/10 bars. outstanding. I've taken the casing apart, the battery is a CR2430 which appears to be at 2.94v, which doesn't seem too bad but I've just ordered a replacement anyway. with the battery completely out of the U/S sensor, LCD is still at 8 bars.

The LCD gadget has 8 jumper type switches on the back -- I'd assume these were matched to the transmitting sensor

quartzz · 5 February at 2:15PM

ok, here are some of those. the large hole is the one you can actually see into. I've never been in this property with "full" oil level. I don't actually know what heating oil looks like (I don't know what a full tank looks like)

I'd assumed heating oil was black and not transparent, and that the liquid in what I thought was a separate vertical compartment was water, and that seeing what appears to be a mirror was an indication that it wasn't contaminated

Looking at the compartment I can see into, I'd guess the level of whatever liquid I am looking at is at about 10%