Scalding hot water

[Bullbags]

New hot water cylinder and new immersion fitted.
After approx. 1/2 hour to hour of the immersion being on get noise (bubbling) from cylinder and the water is way too hot (enough to scold). Have turned down the stat on the immersion but water still too hot.
Any ideas?

 

[seco services]

if you have just turned the stat down you won't notice till the cyl re-heats if its still to hot.

 

[Bullbags]

This has been an on-going issue for a few weeks now.

 

[seco services]

change the stat. it obviously not cutting out at the set temp
how old is it ?
whats the stat set to ?