Will an instantaneous water heater suit my needs?

[neiloneil]

what are these heaters like?
I am considering a "Galxy GX1 Unvented Instant Water Heater 9.5kW (93177)" from Screwfix (£85).
I have a massive old hot water tank which is not very efficient and has started leaking from a pinhole near the immersion element. It now only supplies hot water to a kitchen sink and a wash hand basin. There is maybe 4 to 5 meters of 22mm copper pipe to a reducing tee, then 2 meters at most on each branch. All on internal walls. I would rather mount the heater in the same location, but may consider mounting beneth the kitchen sink. Also, it would be a problem to replace the 22mm with 15mm pipe If this is neccessary.

 

[flameport]

They work, but it's the equivalent of using an electric shower to fill a sink/basin.
For what most people would consider 'hot' it will deliver about 3 litres per minute.
More if you want only warm water.

It is desirable to mount such things close to the outlet to minimise hot water wasted in the pipes.

It also requires a separate 40A circuit from the consumer unit.

 

[Dan Robinson]

Replace the pipes and use the heater

 

[muggles]

Better off having a bit of storage and a lower power requirement

https://www.screwfix.com/p/ariston-...gclsrc=aw.ds&dclid=CMOEqpXg99gCFUog0wodySUC8A

 

[Mottie]

I’ve got an unvented water heater in work, it’s donkeys years old and holds about 10 litres of water. It’s fitted under one big old butler sink that we wash our hands in but it also supplies a small toilet basin 1 metre to the left and one kitchenette sink 1 metre to the right. It’s spurred into the ring main. When all the hot water has been used it takes just 3 or 4 minutes to reheat the fresh supply.

 

[neiloneil]

Better off having a bit of storage and a lower power requirement

https://www.screwfix.com/p/ariston-...gclsrc=aw.ds&dclid=CMOEqpXg99gCFUog0wodySUC8A

This looks the better option. Will it (in your opinion), be ok fitted in the airing cupboard, via the existing 22mm copper pipe?

 

[muggles]

Yes it will, I know this because I've done it for one of my neighbours who is in the same situation as you and they get on with it just fine