an Oil-Tank Monitoring puzzle : Domestic Heating

When I woke, early yesterday morning, the house was rather chilly

… Radiators were stone-cold, and the boiler was obviously not running.

My new abode has oil-fired central heating with an outside boiler.

Opening the box revealed that the boiler had shut-down safely, because it had no fuel. … This was a surprise, because the Apollo ultrasonic monitor showed the tank to be approximately half full [or half empty if you’re that way inclined].

Details of the monitor are here: **LINK**

https://dunravensystems.com/apollo-ultrasonic-standard-level-monitor/

So … I peered into the tank and decided that the boiler’s opinion was good : there was just enough oil to reflect my torch-light, but the tank is effectively empty.

Therefore, the mighty Apollo must be telling porkies !!

I unplugged it from the mains, and had a look at the DIP switches:

1, 2, 3 are ON

4, 5, 6, 7, 8 are OFF

This configuration is not listed on the setting chart in the instructions !!

… so what does it do ?

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I don’t need help, I worked it out this morning

… but I thought some of you might enjoy the puzzle.

In the best ‘Agatha Christie’ tradition; all the clues are there in the document, along with a small shoal of ‘Red Herrings’

Have fun

MichaelG.

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Direct link to the Instructions: 

https://dunravensystems.com/wp-content/uploads/2022/09/apollo-standard-oil-level-monitor-instructions.pdf

… only two pages, and the all-important chart is the top half of page_2

Edited By Michael Gilligan on 28/11/2022 09:56:47

Hi Michael,

I also have oil fired central heating. I used to have the Watchman" ultrasonic level measurement device. It looked very similar to yours.

However the device did not last more than about three years despite new batteries and repeated "pairing". Hopefully your is more reliable than mine was.

Looks like the sw 1 DIP is always ON, the rest of them seemed to be switched depending on the height of the tank. I wonder if it ever worked?

Currently I am using a low tech method, a piece of wood approximately calibrated with levels of 100 litres that I occasionally "dip" to check the level !

All the best

Derek

You have not told us the height of your tank, unless I missed it?

A purchaser of a property with oil-fired heating will normally expect to pay separately for the fuel remaining in the tank at completion. It sounds as though he or she would be well advised to dip rather than rely on high tech gadgets.

.

… Overall height of my tank is 1420, according to the leaflet … so depth might be around 1300

[ but you don’t really need that to solve my puzzle: it just provides a nice checksum at the end ]

MichaelG.

Edited By Michael Gilligan on 28/11/2022 10:47:09

Is the solution somehow "baffling"?!

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No, David … nice try though

It’s strictly down to deciphering that table.

The device appears to be working exactly as it should.

MichaelG.

Hello Michael,

As I see it, the combination 1,2,3 of dip switches applies to any depth of tank above and including 2450 mm and the gauge is not set to read your smaller size tank as the oil level will be 'apparently' below sensing height. Is that correct?

Retiring now for a hot coffee!

Best wishes Brian

I have read the setting instructions twice, and for your tank, the DIP switches 1,3,5 should be up, all others down.

The sequence 1,2..... is for tanks 1800mm height or larger, so your receiver was expecting a larger tank, and hence reported half full when it was actually nearly empty.

Or: The sequence 1,2,5 might have been set in error instead of 1,3,5, thereby making the receiver 'think' the tank was much bigger?

I cannot see how to work that out without knowing the height of your tank? Pray tell.

Edited By John Doe 2 on 28/11/2022 11:14:27

I agree with your analysis, John … but that wasn’t actually the question

What I asked was what setting just 1, 2, 3 ON would mean.

… because that’s how it was set.

MichaelG.

Ah, my apologies for misunderstanding your question. Well in that case, I don't know,. The sequence 1,2,3..... might refer to several larger tank sizes, but with one 'digit' missing or transposed. I cannot see the specific combination 1,2,3 referred to anywhere. Please put us out of our misery !

Switch 1 is just the warning sound enabled. That's why it is always on in the table.

123 is 2425mm depth with warning on.

Edited By Bazyle on 28/11/2022 12:13:26

so depth might be around 1300

1 = 500mm ...eg depth of 500mm

7 = 50 ... eg depth of 550

6+8 = 100.... eg depth of 600

So 650 mm is 1,6,7,8 ie 500 (1) + 50 (7) + 100 (6+8)

Therefore 1,2,3 is ....well, I haven't got round to adding it all up but I think that is the gist of it

Ches

Edited By Ches Green UK on 28/11/2022 12:22:22

Edited By Ches Green UK on 28/11/2022 12:22:51

I've got a similar type remote gauge in mine..

Great until they fill it to the brim which is then touching the sender unit.

It tries it's best - bless it - to work out what's going on for about 12 hours or so then gives up and decides someone is nicking the oil so sounds the alarm in the house - usually about 3AM..

I didn't see if you told us the gauge reading. If the gauge read half full, I can understand why.

Dip setting

Ie 123 on and others all off.

If the dip switch had been put in upside down then the reverse would be trueIe

123 off and 45678 on

That is set for a tank size of 2900 depth and would indicate that your tank was half full. Very clever of the previous occupier if he sold you the fuel !

Edited By Speedy Builder5 on 28/11/2022 12:31:44

Edited By Speedy Builder5 on 28/11/2022 12:32:02

The solution is:

Rip it out and get a heat pump.

Martin

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No, Martin that isn’t the solution to the problem I set

… I just posed a simple question for people to exercise their grey cells upon, not their ‘green’ ones.

MichaelG.

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1. Yes, I said the gauge was showing approximately half full
2. The switches are correctly orientated … and 123 isn’t on the list
3. I did not pay for the remaining fuel …
4. although the Seller did try it on just before completion

MichaelG.

2425

Edited By Bantam Bill on 28/11/2022 13:26:07

what I should have said was that if the switch was in upside down, then 87654 become 12345 and being upside down, OFF becomes ON

12345 indicates a tank of 2900

ie a tank twice as deep, so when your tank is empty, it would show half full on the gauge.

Bob