Ariston Andris Lux 3kW 15Ltr Undersink Water Heater

[Adeh61]

Hi All,

I am thinking of installing one of these heaters.
The online instructions says that it can be installed without an expansion tank if it is 4.2m from a cold water tap.
I have a tap about 3.6m from a standard screw isolation valve. If I connect to the isolation valve the pipe work would be approximately 4.2m from the heater to the tap.
Can someone confirm this is ok or is an expansion tank necessary because of the isolator.

 

[Gasinspect]

In the end I fitted an expansion tank. Got one from Mr central heating for about £13.00

Make sure it is suitable for potable water, they are usually more expensive as have to withstand the fresh oxygen in mains water, whereas the central heating ones are just ok for sealed systems that don't have fresh water flowing through them.