Advice re new immersion heater settings

Susan1942

Last year I had a new hot water tank with 2 new immersion heater fitted.
The lower immersion heater has failed and was replace on Tuesday this week. Cost me a further £120 as it is a large tank and takes a long time to empty. Labour cost was £100 and £20 for the immerser
The previous thermostadt had numbers on it with the temperature which was easy to adjust
The water on this one is absolutely scalding so I attempted to turn it down There are no numbers just a white arrow and an array of marks The Arrow was set to what I thought was the top setting half way round it. I turned the arrow anti clock wise in an attempt to reduce the temperature. I phoned my plumber on his mobile on Wednesday am but he has not returned my call .
I am on economy 7 so the water comes on at night Last night I was awake very late and the water was still heating at around 3 30am I felt the pipes and they were red hot. The water was also very hot so I switched it off. Some years ago I had a failure of a thermostadt where the cold water was also hot one morning. I was afraid this would happen again which is why I turned it off.
My question is am I turning the dial the wrong way and turning the water up rather than down It is 4 30 pm and the water is still very hot despite having a shower a short time ago
Another question When this bottom immersion heater was not working. I used the second heater near the top of the tank. This does not heat unless I flick on and off switch in my kitchen I started flicking this at night thinking that the water would heat at the cheap night electricity rate? Would this be correct? This gave me enough hot water for a shower in the morning and for dish washing etc during the day as I live alone.
I would appreciate any advice anyone can give me. Many thanks Sue

john1

Sue Something doesn't look right here
For instance

Last year I had a new hot water tank with 2 new immersion heater fitted

Immersion heaters normally last 5 plus years

water on this one is absolutely scalding

As far as I know all immersion heater thermostats (which are normally a separate item fitted into the heater body) has a max temperature of around 70C to prevent scalding I may be wrong on this but all mine have this as a max setting.

I turned the arrow anti clock wise in an attempt to reduce the temperature.

This is normally correct

I used the second heater near the top of the tank. This does not heat unless I flick on and off switch in my kitchen

This may be a none ecomomy 7 switch which is a "boost" when you run out of hot water heated via bottom heater

Without having a physical look from your description it looks as if someone has incorrectly wired up your heater and has inadvertently bypassed the thermostat. This would lead to the original short heater life and also the scalding water.

My advise is to contact a local electrician to come and check the installation.

Susan1942

Thanks for that I was not happy about the short life of the immersor fitted a year past in July . It cost me just over £800 for the tank and labour. Think I paid £360' or £380 for the labour . It stopped working in June so 11 months
The plumber said at the time it had a year guarantee When I spoke to him he said the thermostat would be replaced free of charge but would have to pay for the labour
He got an electrician to come and change the thermostat but still did not work
He was supposed to come and arranged a date but did not appear . He failed to answer my calls I had to get a different plumber to do the work .
I will try turning the thermostat a bit further and see what happens.
The plug on the wall is now broken so I need to get an Electrician to change this for me .I will get him to check out the thermostat at the same time I do have an electrician that I use and trust .
Thanks for your advice I do appreciate it Sue

Susan1942

I have just read something that says contrary to what I thought I should turn the thermostat clockwise to turn the heating down.
I took off the cover of the top immersor and it indeed seems to be the case.
I have turned the new heater down and will see how it goes Believe it or not my water is still hot although I didn't switch it on last night as the water was still very hot
It is wait and see now
Sue