Instantaneous Water Heaters - multiple parallel installation

[Nigel Allinson]

I have a very small property in Cornwall with electricity only. The old fortic hot water tank will have to go soon. Does anyone have experience of installing multiple instantaneous electric water heaters in parallel or even in series? The Heatrae Sadia Multipoint installation manual shows how to install in parallel (but it specifically states "do not install in series").

If I had 2 or 3 12Kw units installed in parallel with a PRV on the inlet of each one would that give enough oomph to run a bath tap? I realize I'd need to run a dedicated supply to each one from the consumer unit. The advantages are lower running costs (than a direct unvented tank for example) and freeing up valuable space currently taken by the fortic.

Thanks for any views or experience.

Nigel

 

[SimonG]

W = A x V

Get your water pressure checked. Could go direct unvented or electric combi. But your electricity supply wouldnt be big enough to run 2 or 3 12kw units at the same time.

 

[lame plumber]

upgrading to 3 phase can be a bit steep on the cost side!

 

[Ermintrude]

Bio bio bio mass

 

[lame plumber]

un vented direct cyl easiset option for small cornish property

 

[Ray Stafford]

This one keeps coming up Nigel, and I am afraid the answer is always the same.

Not on single phase UK domestic power. Your max is (roughly) 11kw.

You would need to upgrade to 3 phase, or re-think and store some water. If your mains pressure and flow are OK, consider an unvented direct cylinder as per SimonG's suggestion above.

 

[Gray0689]

Or go for a wood pellet stove linked to an unvented cylinder
Expensive but then the grant will help a lot

 

[Killy Bing]

Running costs wont be lower !!!
Not with that set up
you would be drawing a huge amount of juice while in use.

put your kettle on and watch it fly around.
a kettle is about 2 kw

you want to run a pair of or three electric heaters
thats 24 or 36kw!!

Have an lpg intergas combi installed and have it set to water heater mode.
leave power on to it when you're not living there and it will be fine 🙂
also if you decided you wanted a wet central heating system the boiler can be turned back to a combi with a few setting changes.

much cheaper than bumping upto three phase.

 

[Ermintrude]

Why not go solar thermal and bio? You will get paid for it? Although if it's a second home u may need to be creative!

 

[Killy Bing]

Why not go solar thermal and bio? You will get paid for it? Although if it's a second home u may need to be creative!

space is the issue.
wants a smaller foot print

 

[Ermintrude]

Oh, external ? What about oil combi they are amazing? Ashp solar in loft?

 

[Killy Bing]

What about oil combi they are amazing?

having a giggle right?

if its a second or holiday home then everyones overthinking this

 

[Ermintrude]

Oil combi
Oil combi
Oil
Oil
Oil

 

[Ermintrude]

Ohhhhhh neta tec on lpg

 

[Killy Bing]

Ohhhhhh neta tec on lpg

have diverter to and pump to go then

 

[Nostrum]

A very small property with 3 baths?

Killy's suggestion is the best if you have a suitable space to store a set of cylinders.

 

[Ermintrude]

Be nice , big thermal store