which immersion do i use?

[lilynmax]

i have a water tank with two immersions, one at the bottom and one at the top, I am on economy seven heating but I have no idea which immersion should be turned on to gain night heated water! I tried to do a test to see which used less electricity but I didn't have much difference, I currently have the top one on continuously and the bottom one permanently off, but is this wrong?

[CSG2306]

Hi Lilynmax,

Yes, Hot water rises through the cold water heating the cold water as it passes through.

You are only heating the water in your tank that is above the top heater.

To heat all of the water in the tank you must use the bottom heater.

The idea of a top heater is to give you a little hot water in a few minutes. I.E. for a quick dishwash if the water in the tank is cold.

Regards

[lilynmax]

thanks, I understand I'm only heating the top part and I don't use much hot water as I have an electric shower, but which immersion works out cheaper? Am I paying a fortune using the top one - is it heating up constantly when perhaps the bottom one will only heat at night when it's cheap? Sorry if I'm a bit stupid but I know next to nothing about plumbing etc!!

[heathfield]

It's ususal for the bottom one is on 'offpeak rate', while the top one is on full rate.
It's easy to check by placing your hand on different parts of the tank at various times during the day and evening.
Both elements will be under thermostatic control. The upper one won't be heating all the time. Once the upper water's heated up, it will just switch on from time to time to maintain the temperature.

[tezestwing]

Hi lily If it is connected up correctly then the bottom one is on economy 7 and should be left on all the time as csg2306 and heathfield has posted the best way to check this is to switch the top one off and leave the bottom one on the then in the morning if you don't have any hot water( I bet you do though) you need them re wired ( by a competent electrician) the hot water that you have should last you all day if you use it with care until economy 7 comes on again approx 12 till 7am or 7 hours if you do run out then that's were the SHORT TOP immersion comes in because it should give you a quick boost of hot water within a few minutes then you can switch it off when you have had enough HTH Tez

[tezestwing]

Hi again lily just seen pea pods post in home and garden about economy 7 HTH Tez