immersion thermostat keeps failing

[panny300]

anyone know why immersion thermostats would keep failing,had about 3 in last six monthw,the tank is smaller than a normal one,shorter and thinner,first problem was only the top 9" of the tank was getting warm and it had already had a couple of thermostats,
it's for a freind who rents the house, so i took the element out and it seemed a bit short for the lenght of tank.not being a plumber i advised him to get one to check it,he thinks the plumber fitted a new longer element and new thermostat.
got a call saying no hot water again and he could'nt get the plumber out,so asked if i would have another look,the reset button had popped out of the new thermostat,i clicked it back in and said see how it goes,but there must be a reason it has overheated,anyone any ideas why he's having these problems.

 

[libby lou lou]

Are you a sleeper?

 

[Agile]

You seem from your many questions that you do work as an odd job man including gas boiler and electrical work that requires training and registration.

Quite apart from the questionable aspects of doing these jobs, do you have public liability insurance?

 

[petit_pablo]

Whats the temperature of the thermostat on the immersion actually set too?

 

[sooey]

I've seen these pop out when an electric card meter runs out of credit and the card is topped up.
I had an old lady customer with that problem on an immersion I'd fitted, after I told her to turn the immersion off before topping up the meter I didn't hear from her again.

 

[panny300]

whats a sleeper? and i am not a paid odd job man,i always do my own odd jobs so have picked up a bit of knowledge along the way,and in doing so,i get asked by friends and relatives about any basic problems they have,if i can't help i come on here and ask,i thought that was the purpose of this forum.
if you noticed in my post i advised him to get a plumber out as i thought it best to get a professional in,who then would'nt come back.
petit,the thrmostat is between 60 and 70 deg.
sooey that sounds as though it could be the reason,i will advise them to do the same.thanks