Emersion heater length

[user 37014]

Long story.

I'm in the process of buying a solar diverter for my hot water, but before I do, I'm conducting a few hot water experiments.

In the 25 years we've been in this house, we've never relied on the emersion heater for hot water, it's only ever been used as an emergency top up service.

Also as we've been working during the day, we've never been able to use the emersion heater as our main source, as we are not here to switch it on and off.

However, now retired and at home a little more, I can now flick the switch manually when we are generating an excess of solar.

This week (being sunny) has been part of my trials, and I've noticed that we don't get a full bath of DHW when using emersion heater only.
We maybe only get half of what we would had we used gas.
Its fine for showers, but not enough for a full bath.

So:

I've considered that the top entry emersion heater may not be full length, and only giving us half a tank of hot water (makes sense).
However there are no part numbers on the element, which would indicate its length. (Pullin 240v 3kw)
The simple solution would be to take it out and have a look, but i'd prefer to avoid this for obvious reasons.

I took the end cap off to look at the thermostat and along the bottom of the stat it says 18".

Do I assume that the element is 18" in length
or does this mean that the desired temperature which is set at 70 degrees is at 18" depth.
I've upped this to 80 degrees to see what difference it makes

 

[UNG]

An 18" stat would suggest that you have a 27" element if it was an 18" element the stat would be 11" long

 

[kerching]

I had a customer who successfully managed to hammer an 18" stat into an 18" element
He had to hammer it as there was some obstruction.
The obstruction being at the end of the 11" stat pocket
Whoops

 

[apprentice87]

I would say that the heating element is knackered. I have seen where not much hot water has been produced and on removing the thing is was discovered that the element had turned green and was burst open for much of its length. I would assume that it is only because water is not much of a conductor and thanks to bonding that i am able to be sitting here typing this..

john..