Just had my oil tank filled, got a concern....

aliasojo

2500L tank, remote 'Watchman oil level plug thing in kitchen.

We have only ever put 500L or 1000L maximum in the tank previously.

This time we got 2000L. Before delivery, we knew there was some oil in the tank but not exactly how much, the Watchman thing was showing '1' with a flashing light, after delivery it shows 'F' which I'm assuming means full.

The other day (before the latest delivery) I noticed the Watchman changed between 1 and 2. OH said it was because it was a warm day and expansion was taking place. By evening it had dropped back down to the flashing '1'.

Now my question is, there's so much more oil in there now, if it all expands again and the tank is very full, what happens then? It wont burst or cause a pressure build up which will strain the tank will it? I wouldn't have thought so but I'd like to be told for sure. I'm hoping there is some sort inbuilt thing that takes this into consideration but I've read on the net about people's tanks splitting which concerns me a bit? I don't know if it's single skinned or bunded btw.

malc_b

Are you sure your oil hasn't been stolen?

On my watchman the number represent the oil level so depends on the shape of the tank to what the exactly mean. 0 = 0 to 10%, 1=10-20%, ... 9 = 90-100%, F = FULL (i.e. stop filling NOW for lorries with the matching kit).

If you still have oil in your tank then it sounds like the watchman is faulty or the batteries need changing. If the batteries then this might be of interest.

http://www.susa.net/wordpress/2012/03/oil-watchman-power-tube-batteries/

aliasojo

I honestly don't think you've read my post correctly.

HappyMJ

aliasojo wrote: »

I honestly don't think you've read my post correctly.

The watchman is only a guide. It's not very accurate.

aliasojo

Why is everyone getting caught up in the Watchman thing, my question is about expansion?

The Watchman stuff was only included to show previous expansion took place with little in the tank so I wanted to know what would happen if expansion took place when the tank was full?

aliasojo

I've just reread my first post and I'm still not sure how my actual question was missed but I've tried to clarify. If it's still not clear, let me know and I'll completely rewrite. :rotfl:

peachyprice

I can't answer your question, but it seemed perfectly clear to me

You'd like to think that an expansion gap was built in, hopefully there is, especially as the weather has turned nice again.

aliasojo

peachyprice wrote: »

You'd like to think that an expansion gap was built in, hopefully there is, especially as the weather has turned nice again.

Yes, exactly. Thanks.

manda1205

I always though when mine was flicking between pips its because its on the border of that mark, not because of expansion. Ours has now been filled and we're full on 10 but sometimes it flicks down to 9, Im guessing because the tank man doesn't fill it to brim, he leaves it just under (when you look in the tank you can see there's a gap), maybe this is for expansion reasons? Have you looked inside your tank, in the top?

TiredGeek

How big is your tank?
If it's a 2000 litre tank there'll be about 100 litre expansion / overfill safety margin so you'll be fine...
If however it's a 1900 litre with 2000 in then you're in trouble

malc_b

I think I see. When you say by evening and before latest delivery in the same sentence it sounds like you mean, reading 1-2, oil delivered, reading1. Really just leave out the before oil delivery and the sentence then makes sense.

Yes kerosene, aka heating oil, expands with temperature, as do most liquids, water being the notable exception which is denser at 4C than 0C which why fish aren't fish fingers in the winter.

Kerosene is 0.1% / C

But the tank will get slightly larger too. Tanks normally have a built in allowance for this so my 1200 l tank has a gross capacity of 1300 l (AFAIR).

You probably also get drift of the watchman value with temperature even if the heating oil level was fixed.