What oil tank gauge is this ?

[SimonH2]

This is in the tank at the church hall, I suspect the battery is low or flat.
A while ago the display was alternating between a reading and "c", now it's showing "r", and the red LED is flashing.

When I try searching for instructions, I get lots of hits for the newer types, but few that look like this. Beyond being Watchguard, I don't know what model it is.

What model is it, and is it easy to change the battery ?

 

[muggles]

The official batteries for this model are now discontinued and have been for some time. It is possible to whack the cap off the end of the copper battery tube and replace the batteries within, but be careful not to damage it

 

[Exedon]

As above aaa battery's in tube there is a loose spring under cap careful not to lose it!
Batteries need to be good quality duracell or similar.

 

[SimonH2]

Thanks. So batteries in the tube sticking up on the left, and it unscrews ?

 

[Exedon]

Tube unscrews then copper cap need knocking off.
I use a bahco type adjustable spanner adjusted to fit copper tube then slid up and down to knock off cap.

 

[SimonH2]

Thanks, I'll be that way tomorrow and give it a go.

 

[SimonH2]

Gave it a go, the cap came off without too much of a fight, luckily to person stood next to me spotted where the little spring went on the floor - and I was being careful
4off AAA later and now the display has stopped flashing "r", now it just shows "0" and the red light flashing, which I assume means "really you should think of putting some oil in pronto". Now to find out where the supplier put the 500l they say they delivered - my suspicion is it went in the vicarage tank which has gone up from 1/4 to 1/2, and that's not ours