PLEASE HELP economy 7 / hot water cylinder / electric

sarahbrown58

we moved into a new house and the hot water cylinder (which is direct and copper, it has an immersion at the top and an immersion at the bottom) began to leak so this was replaced. The plumber rewired it up as it was previously, which was wrong... the override boost switch was wired to the bottom and the night rate was wirded to the top thermostat. That is how it was wired when we moved in.
So i get out an electircian who rewires it, but there is a problem the night rate switch was not working. so the same electrician changed the switch and it worked perfect as it should - bottom thermostat coming on and heating up water overnight... top one working as and when required.
PROBLEM...
today the bottom thermostat has started to come on throughout the day in the same way the booster thermostat would if that was switched on and the pipes are VERY hot. so i have switched it off.

whats going on?
please advise

dieselglider

Sounds like the night rate switch has gone faulty, or a manual over-ride has been switched on, if it has one.
Is the night rate switch a timer, if so, can you check if it's set correctly?

sarahbrown58

i dont know where the timer is as it is not accessible, we only have access to two switches - one the override and one the overnight.
interestingly the storage heaters were also kicking in all day yesterday and becoming very hot so i had to switch them off too!
basically it seems that electric was going to all appliances that are set to go on at night
more interestingly they are all working fine today!
any other isdeas/further thoughts MUCH appreciated!

thanks

sarah