Bathroom & Kitchen Water Heating - what's the best system?

[LeanTwo]

I am looking at creating more space in our bathroom so the space taken up by an airing cupboard has come under scrutiny.  Currently, all of our household hotwater comes from an indiect vented "Economy 7 " cylinder with two immersion heaters.  Therre is no gas in the village. A small additional boost is given from an internal  copper coil fed by a copper "boiler" in our multifuel stove.  The dimensions of the boiler are approximately 300mm x 150mm x 25mm.  It has its own FE supply.

 

The world has moved on since I installed all of this 35 years ago!  Poking around on the internet, I have come accross tankless/instant water heaters and thought that they would be worth having a look at.  The airing cupboard and cylinder would go and be replaced by some more modern water heating system.

 

The things that I am looking at are as follows.

 

1. Are the instant water heaters more efficient than the system that I have at present?
2. Do I supply an instant system from my loft FE supply, currently conected to my immersion cylinder or is it a rising main that would do this job?
3. Would all of the instant hot water come from one heatingappliance or would I be better of finding the approriate instant heaters for each outlet such as a bath, shower, hand basin, kitchen sink etc?  I  have seen some very neat appliances that fit under a bathroom hand basin.

 

The house has three bedrooms, one bathroom and currently three occupants.

 

Any reccomendations, experience or advice would be welcome.

 

[JohnMo]

Why not look at a cylinder with heat pump built in.  Needs an internal and external air supply, something like a Dimplex Edel (other makes available)

 

Will use a 1/3 of the electric you use now.

 

Instant water heater will use peak rate electricity so you don't want to go there.

[LeanTwo]

Hello JohnMo

 

Thank you for your reply.

 

I've had a look at some heat pumps and the principle seems sound.  I guess that such a system would be fed from the rising main?  A single pump would be able to provide all our hot water by replacing the current hot feed to the shower, bath, hand basin, kitchen sink etc?  Calculating the output accurately so as not to under or over invest would be very important.  I would unfortunately, have to give up my idea of doing away with the airing cupboard as the cylinder/pump would need to go somewhere.

 

Have you come accross a comparison site for the various methods of heating domestic water?

[Nickfromwales]

You will struggle massively to replace the bulk of stored water provided by your current cylinder tbh. 
To go to an instantaneous water heater for your needs would require 3 phase, as the single phase ones are utter garbage for flow rates. 
Do you have an electric shower? 
Do you have an attic ( where I assume your F&E tank(s) currently reside?

You could relocate the cylinder, replace with an unvented cylinder ( UVC ) amd go horizontally in that attic ( if there’s room to do so ). 
No magic little gadget is going to do this I’m afraid, other than the 3 phase Steibel Eltron 27kW instant. 

[LeanTwo]

Thanks for your reply Nick and the advice on 3 phase, where, no doubt, additional costs would arise.

 

Our shower hot water is drawn from the immersion cylinder on a gravity feed.  If we run low on hot water, which is rare, we switch on the upper immersion heater, outside of our Economy7 hours. We have no instant water heaters.

 

We have an attic, not that high (maybe 1.7m at the apex), but built to modern building standards so it would take the additional load.  The two F&E tanks are also up there.  Not understanding these things well, would the cylinder have to be lower than the main F&E tank so as to allow a gravity feed to work or is that the reason that you sggested an unvented/horizontal tank?

 

Is there room in the attic?  Of course not, it's rammed full of stuff we never need.  It would provide a good excuse to "review" it!

Edited September 24, 2022 by LeanTwo
Additional clarification.

[Nickfromwales]

16 hours ago, LeanTwo said:

Not understanding these things well, would the cylinder have to be lower than the main F&E tank so as to allow a gravity feed to work or is that the reason that you sggested an unvented/horizontal tank?

An UVC is cold mains fed ( the force of the cold mains pushes the hot water out, so no pumps / gravity / F&E tank(s) required ) so you would get balanced hot and cold pressure throughout the house if you go fit this type of conversion. 
 

Some pics of a previous clients install with a 250L horizontal Telford cylinder. 
 

 

With a system like this, your showers would be much better ( and longer ) and you can have dual immersion too. I’ve added a pic of the end where you can see the immersion.