Recommendations - Economy 7 Hot Water Replacement

[fayfay]

Hello!

I have recently bought a 2 bedroom, electric-only flat with a current setup of an Economy-7 powered immersion tank and cold water storage. The system is about 20 years old and I would like to replace it, but it looks like there are so many options (a replacement of my current setup, an unvented system, a combi boiler(?), a thermal store...) The things I'm trying to take in to consideration are:
* Space - The flat is very small so if there's any way of getting extra storage space by ditching the cold water tank, great!
* Usage - I only use hot water for dish-washing, and a bath about once a month. I have an electric shower.
* Rental - I would like to rent the flat out later down the line, so I guess i need to consider future usage above my own current low usage.
* Timers - There are currently only 2 switches to the immersion tank, meaning that Peak and Off-Peak can only be on or off all the time - this is very wasteful as I do not need the tank heating up all night every night. Is replacing these switches with a timer possible, and is that a totally separate job?!
* Pressure - The current pressure is not fantastic, but to be honest not much of a concern due to the electric shower.
* Price - Price is not so much of a factor, I would rather get the right system for the right job than bodge it.

I would love to hear your recommendations on what type of setup I could get - I was going for an unvented system to ditch the water tank, but then I heard about the yearly service which put me off a bit - would a thermal store save the same space but forgo the need for annual servicing? Any advice very welcome thank you!

 

[OwainDIYer]

* Timers - There are currently only 2 switches to the immersion tank, meaning that Peak and Off-Peak can only be on or off all the time - this is very wasteful as I do not need the tank heating up all night every night. Is replacing these switches with a timer possible, and is that a totally separate job?!
* Pressure - The current pressure is not fantastic, but to be honest not much of a concern due to the electric shower.

Are there two separate immersions for peak and off-peak?

If two, you can get a boost timer for the peak heater
http://www.tlc-direct.co.uk/Main_Index/Timers_Index/Immersion_Heater_Timers_2/index.html

If one heater, then immersion heater controllers with a boost function are available
http://www.tlc-direct.co.uk/Products/SMTRTM7.html

The cylinder will only heat up overnight until the thermostat cuts out, and if it's well insulated will retain the heat until the water is used, or will use less heat the following night.

If you have a separate cold tank and hot cylinder then you could pump the output, but if it's a combined H&C 'fortic' cylinder then these don't usually respond well to pumping.

For renting I would retain what you have as being simple and reliable; the electric shower and the immersion give two sources of hot water so if one fails you do not have to do expensive emergency call outs as tenants can manage with the other source for a couple of days.

 

[dcawkwell]

Combi boiler will work fine provided there is gas. 30kW
Keep the electric shower as a backup.

 

[JohnD]

electric-only flat

is gas available, or not?

When you fill a bucket at the kitchen cold tap, and time it, how many litres per minute do you get?

 

[fayfay]

No, gas is not available at all

Thanks for the replies guys! Especially Owain, those timers are exactly what I'm looking for, and on reflection I think I'll definitely start by getting the immersion tank serviced + thermostats replaced, and a new water tank - that shouldn't be too expensive and as you say it's nice and reliable - then if I want something fancier in a year or so, I won't have sunk a large chunk of money.

Thanks again!