Polesapart, I would - but the immersion element is inside the cylinder so it's kind of difficult to measure it! That why I asked the question of whether anyone knew the model number.
Even when the immersion is on until it stops (i.e. its internal thermostat turns it off, which I can tell because I have an electricity monitor) there isn't a full tank of hot water. Most of the time we heat water by gas and that does give a full tank (because the coil is at the bottom...
See attached pics, thanks.
I wondered if the 270 was mm i.e. 10.5 inches.
There was a little Shel product leaflet tucked into the top of the cylinder. It only mentions thermostats of three lengths: SS7 (7") SS11 (11") and SS18 (18", no surprise!). There no mention of an XB270.
My indirect HW cylinder has a top mounted immersion element labelled “Shel CODE XB270”.
Does anybody know how long this is?
The cylinder says “Max length immersion 760mm”. I suspect that the one fitted is much shorter than this and is only heating the top portion of the cylinder.