Water heater timings using Economy 7 tariff

Mr_Gwent

Hello

I have recently moved into a second floor flat which has a hot water cylinder supplied by a tank the previous occupant had installed in the attic of the building. The flat is on the top floor and has access to the attic.

My questions concern when the hot water cylinder should 'charge' or heat water according to the Economy 7 tariff. The cylinder is rather conventional and has two thermostats both set to approximately 50 - 55C: neither thermostat has a timer. The immersion, which I leave on all the time because of what I read, connects to the lower section of the cylinder, and the booster connects to the top. I normally leave the booster off.

Can anyone tell me if I am right in thinking that the immersion should only heat water in the cylinder during the night when the Economy 7 tariff is active?

Assuming no use of the hot water on a given day, should the immersion work during the day to heat the water which will inevitably cool somewhat? Presumably, the same would be true of water usage which would cause the cylinder to refill somewhat.

How long should the cylinder take to heat anyway? I ask because shortly after 1600 hrs today, heating water took almost half an hour and the hot water had not been used beforehand. This is outside the Economy 7 time in my area.

Also, is any reader aware of any good water level sensor for use in an attic tank which could be used to detect overflow, should that occur either through ball !!!!!! valve failure or water getting into the tank via the expansion pipe?

Thanks

Mr Gwent.

Ectophile

If the cylinder is well insulated, it should stay hot all day, unless you use the water.  If you have E7, set the main immersion heater to come on at night only, so you have a piping hot tank of water in the morning.  Then use the booster as an emergency top up if you ever run out of hot water during the day.

If you leave the immersion on all the time, then you're heating the water with expensive peak-rate electricity for no good reason.

Mr_Gwent

Thanks @Ectophile for the reply. But I should have included in, but have now added to, my original post the detail that neither thermostat has a timer, but that does not stop me from switching the immersion on overnight and off in the morning.

I have also been told that leaving the immersion on constantly is the best policy.

Richie-from-the-Boro

How do you heat the rooms in your home ? Are they also E7. GoTo your online account and get actual factual information:

- supplier name ?
- tariff name on contract ?
- your contract (not deemed) ?
- E7 or E10 ?
- you supply 6 weekly factual meter reads ?
Most E7/10 water cylinders are PartL standard top grade insulated indirect vented and have a two stats/element top and bottom (25% bottom 75%). Both are controlled by a 'water controller' the top one is boost only for timed short periods the bottom is available for the whole 7 hour period. Convection will eventually heat the entire volume from the bottom. Your water should not heat on E7 in the afternoon unless you set the timer. Want more - ask my friend. Best of luck.

Mr_Gwent

The heaters in the flat are storage heaters that run on E7.

Gerry1

Leave the top (boost) immersion heater switched off.  Have a look at the switch for the lower immersion heater: does it have a neon indicator?

• If there is a neon indicator that only illuminates during E7 cheap rate hours, that's fine and you don't need to do anything else.  (If you run out of HW in the evening, use the top heater sparingly and don't forget to switch it off).

• If there is a neon indicator that's on 24/24, ask the landlord to provide a separate E7 meter-controlled off-peak circuit for the lower heater.  However, he'll probably be a cheapskate, in which case you'll have to settle for a local timer to shadow the meter clock; look at the meter so see when it switches over.  Make sure the timer is electronic with a battery backup, not a motor driven one that will go out of kilter after a power failure and put your bills up.
  

• If there's no neon indicator, switch it off and let the water go cold.  Then switch it on in the daytime or early evening.  If the water soon starts to warm up, get a switched circuit or local timer as above.
  

Mr_Gwent

The immersion switch has a light which is lit when the immersion is on, i.e. all the time at the moment. But I will have to look further for any other lights.

CheBee

This might help?

https://www.youtube.com/watch?v=peigUF5286k&list=PLbTUKnfFk1w7gG-zXCOhBE2nCg5PHPo_0&index=2&t=0s

This helped me when I moved into my flat. I didn't realise that I had the boost setting on ALL the time and my electricity bill was so high! 

Gerry1

Mr_Gwent said:

The immersion switch has a light which is lit when the immersion is on, i.e. all the time at the moment.

The lower heater or the upper heater?  If the lower heater is on a 24/24 supply that's bad news.

Mr_Gwent

The immersion is the lower heater which I have been recommended to leave on at all times. But I may start switching it on only when I need hot water.

Talldave

If the neon light is on 24 hours a day, that's bad news. You need to replace the switch with an immersion heater timeswitch. Set the timer to come on for 2 or 3 hours in a morning just before your E7 period ends. This end time may be different during BST & GMT, monitor the meter to find out when it's switching. Whilst you're replacing one switch, think about replacing the Boost switch with a 30min/1hr/2hr timer switch designed for immersion heater use.