Under Sink Heaters a couple of quick questions....

[Adam Aglionby]

Had a look through the archive but still have a couple of questions.

Gas not being an option unfortunately, looking to replace header and immersion tanks with some form of `undersink ` heating. To supply kitchen sink and showeroom basin , replace current dribbling shower pump, non power shower :-( , with electric shower.

Uvented Undersink appears to mean under a sink at least 4 meters away for some models though, is this total?

Or can you have a tap tee`d below the 4M limit but overall pipe length to second tap extends to the limit?

Is it better to have a the heater at the washing machine/sink or bathroom/ex-water tank space?

Is a copper tank heater that much better than a Screwfix

type thing, enameled steel tank?

Is a 9.5kW flow boiler a better solution?

Thanks for any help.

Adam

[Dave Plowman (News)]

Might be ok for a single person who is out all day and lives on take aways. For someone who cooks - or a family, totally useless.

[Adam Aglionby]

Thanks for the input but its a tiny one bedroom flat where the cubic space taken up by the cold and hot tanks would make more sense as storage.

15L of hot water more than enough to fill both available sinks, showeroom one is of railway carriage size...

Combi/condensing gas boiler would be preferable but not an available option on this project.

Had one water outage ever, so unconvinced by reserve water supply reasoning, specially for drinking water, seen inside a few header tanks, or aquatic micro zoo may be better name.

Any direct experince anyone?

Thanks Adam

[Pete C]

Hi,

The instructions on mine state it's to accomodate any expanded water so it should be OK.

Depends on the length of the pipe runs, they will reduce the capacity of the heater effectively and waste some heated water.

It depends on how much water you require, I reckon a 15L though a TMV would give you 25L of shower temperature water but pipe runs will reduce that.

There is a 30L model available from somewhere, I could try and find it if you want.

Depends on how much you would need to spend on extra wiring as well.

Another option could be to use a higher grade (pressure) immersion tank with an expansion vessel connected to mains via a pressure reducing valve, though this is not a 'normal' way of doing things.

cheers, Pete.

[Christian McArdle]

This is because it doesn't have a built in expansion vessel and uses the supply/tap pipework for the same purpose. Buy the type that does have an expansion vessel and you lose the pipework length requirement.

Christian.

[Pete C]

Hi,

If funds aren't a problem and the supply is up to it the best option might be to get the most powerful electric shower you can.

Another option would be to have 2 15l heaters in series. One could be switched on for washing up water and both for a shower.

This should give you at least 50L of water at shower temperatures using a thermostatic shower valve, which works out to a 5 min shower at 10L/minute which is not tooo bad.

How powerful a shower feels depends on the pressure as well as flow, it depends on whether you want to rinse shower gel off or have a vertical bath :)

cheers, Pete.