Undersink Heaters

[P_D_G]

I'm adding a bathroom & although I'm happy to take the bath hot water from my combi, the piperun length is too long to be satisfactory for the sink - I'd probably leave 5 times as much hot water in the pipes as I'd use in the sink.

Can anyone recommend a cost effective undersink unit? My guess is that the 9.5kw instant ones won't be hot enough & I'm not sure how much power wastage there is with the 5/10/15ltr, 2 - 3kw preheated varieties. (ie, if the sink is in use twice each morning & twice each evening, how well are they insulated & how much heat loss is there during the day etc). (Just thought - could I put one on a timer?).

Thanks for any advice.

 

[breezer]

combi is easier, less hassle

 

[ChrisR]

Just fitted eight Ariston unvented undersink heaters - but Thames water is involved so the property has had no water for months - onother story!!

The Instant hw devices don't give you much and you need a big electricity supply. The Vented under or oversink 3kW storage things mean you have a tap which has to be allowed to drip - a special expensive one for an Undersink type. If you use an unvented store you will need a pipe going through the wall as a pressure relief pipe in case the thing ever boiled, and a check valve, tundish and small expansion vessel, A lot of people go against the mfrs intructions and miss out the check valve, tundish and small expansion vessel - but I couldn't advise that. If your mains pressure is enormous you'd need a pressure reducing valve as well.

Those bits aren't a big problem to fit, they just take some space. The Ariston units come in 2 or 3 kW, 10 or 15 litres and are about the cheapest. They are v well insulated but yes you could use a timer if you wanted.

 

[TheIce_Man]

I wouldnt touch anything by ariston as they are so unreliable it is a joke