Heating oil delivery issue

JeffinWales

I see there was a short thread on this subject back in March 2011 but nothing since. I recently had an exact same issue with this a few months back. Like the former poster I am meticulous when it comes to recording utilities of every kind, not just heating oil but electricity, water and PV generation. I had a new bunded 1300 L tank installed in Sept 2021 and the oil tank manufacturer, on my request, supplied me with a calibration chart. I used the data therein to make my own dipstick.

I have had 9 deliveries of oil since then and all bar one were almost precisely the quantity I ordered using the dipstick to determine the amount required. I usually order when the tank is about half full, hence around 600 - 700L. I was suspicious in this instance because the calculated amount, which should have completely filled the tank, was apparently about 80 litres short. This had never happened before. This incident coincided with the appearance of a new delivery driver - the previous guy had retired. So this was a rather tricky position to be in as you can imagine! 80 litres difference in 1300 litres is a lot to be explained by expansion or contraction I would have thought?

How many customers would know exactly how much oil is in their tank before filling up - there has to be complete trust in the oil supplier and/or the suppliers equipment. I presume there is some sort of pump calibration protocol which suppliers must comply with and the data scrutinised by Trading Standards?  The docket I was given showed a before and after reading and indeed it was the quantity I had requested, so what else can I do?

I did contact the supplier in this case but of course all they could say is that as far as they knew all their equipment was functioning normally!

I will be ordering a top-up in the next week or so - it will be interesting to see how we get on! This time I will show the delivery driver the dipstick reading before he starts pumping oil and again at the end rather than just leave him to it.

 

CliveOfIndia

With the best will in the world, a dipstick is never going to be accurate.  It's good enough for the end consumer to get a rough idea, but it's impossible to calibrate exactly.  Even simple things like holding it at a slightly different angle will give different results (don't tell be you use a spirit level to make sure you're inserting in perfectly perpendicular?).  And do you insert it in precisely the same place each time?  It's not unusual for the bottom of a tank to be ridged or slightly curved, depending on whereabouts you're dipping it.

JeffinWales said:

I presume there is some sort of pump calibration protocol which suppliers must comply with and the data scrutinised by Trading Standards?

Indeed there is, just the same as the petrol pumps on a garage forecourt.  If you really think they're pulling a fast one, ask your local Trading Standards to pay them a visit.

lohr500

Forgive me for asking, but Is it possible that you misread the dipstick before the delivery was made and the oil was actually lower than you thought? 

If the delivery was 600 or 700 litres, then an 80 litre discrepancy is very high and it would be highly unlikely for the pump calibration to be that far out (although I guess not impossible).