Which water heater

[Louby Loo]

Hi, I need to replace a water heater. Actually, we have two at the minute - a 2kw 5L Zip Contact storage heater over the sink (which has it's own vented pipe attached), and a 3kw Redring handwash over the washbasin. It is the handwash that is faulty and the plumber has said if I get another, he will replace it for me.

However, seeing as though the 2Kw water storage heater is a bit old and limescale encrusted, the electrician has suggested it may be worthwhile replacing both by getting a 10L under sink water storage heater that could supply the sink and the washbasin (neither of which gets much use). I see that there are vented ones ( which would mean replacing taps with vented taps) and that there are unvented ones that must be fitted with a pressure release valve discharging to a drain. They sound good because we wouldn't have to replace the taps. But I'm confused as to whether an unvented system means it must release to an outside drain or to an internal waste pipe. Would be grateful if someone could explain this.

I can't contact the plumber at the minute because he's away on holiday but was hoping to order something suitable in the interim because the electrician and plumber are coming down to do the work when the plumber is back from hols.

So before I go and order something that is a complete disaster, I would be grateful if someone could advise if there are likely to be any pitfalls to ordering an unvented system, and what this pressure valve drainage actually entails. Or do you think I had better stick to just replacing like with like and ordering in two water heaters similar to what we had before?

Thanks

 

[stevetheplumber]

Preasure relief has to go to drain often in to washing machine trap if below sink unit

 

[Louby Loo]

Thanks Steve,

We haven't got a washing machine trap. There is only a sink, but that sounds like it wouldn't be an obstacle. I guess the plumber could put in something like a washing machine trap. So does it just have a hose attached like a washing machine or a dishwasher does to drain the waste water? So long as we don't have to start drilling through outside walls or anything major like that....Was thinking about an inline water heater but at 9.5 or 12KW the electrician says current wiring may not be heavy enough for this so has advised against it.

Does an unvented 10L water heater sound like a fairly cost effective solution to fit and are there any other pitfalls I need to be aware of? Would certainly prefer this since I think the over sink/basin water heaters look a bit rubbish. Much nicer to get hot water out of an actual tap...

 

[tube fitter]

i recently fitted an ariston unvented 15l 2kw in a vets practice it runs 5 hot taps fine, as for the pressure release valve it can vent anyware you choose

 

[stevetheplumber]

i recently fitted an ariston unvented 15l 2kw in a vets practice it runs 5 hot taps fine, as for the pressure release valve it can vent anyware you choose

weve fitted loads in goverment offices and the surveyors insisted they went to drain so we used stab in washing macine traps below the sink with 3/4 F/I screwed on to the stab in and reduced to 15
some of the kitchen units had hydro boil units a water heater and waste saniflows right bugger getting that lot in plus a no heat rule and no flexis so all in pushfit copper