Grohe tap fitting 15mm flexi vs 21(?)mm valve thread

[Boothus]

Hello,

I’m trying to fit a new Grohe tap. Flexi hoses are 15mm and don’t fit the 21mm (guessing it could be 22mm?) existing thread on the water feed valves. See pictures attached.

Is there an adapter I can buy?
Or do I need to replace the valve for a 15mm one? The copper pipework itself for the feeds is 15mm.

Thanks,
Ben

 

[Riley]

Bath tap

 

[ShaunCorbs]

3/8th thread

1/2 normally measures around 20mm if smaller then its 3/8th

https://www.NoLinkingToThis/p/brass-compression-adapting-flexible-tap-connectors-15mm-x-2-pack/2665r

https://www.NoLinkingToThis/p/brass...exible-tap-connectors-15mm-x-3-8-2-pack/6089r

you still got the top nuts for the iso valves if not your going to need some and a replacement olive

 

[Boothus]

Bath tap

Not sure I follow...

 

[Boothus]

3/8th thread

1/2 normally measures around 20mm if smaller then its 3/8th

https://www.NoLinkingToThis/p/brass-compression-adapting-flexible-tap-connectors-15mm-x-2-pack/2665r

https://www.NoLinkingToThis/p/brass...exible-tap-connectors-15mm-x-3-8-2-pack/6089r

you still got the top nuts for the iso valves if not your going to need some and a replacement olive

Sorry but can you explain how to take measurements to make sure I get the right ones?

Does the olive go on the adapter and then the top nut goes on there?

Thanks

 

[ShaunCorbs]

easy way do the flex nuts fit onto the valves in the pic if not its 3/8th

as for the valve / fitting

adapter
nut
olive
valve

thats how it should go together

 

[Burger]

Hello,

I’m trying to fit a new Grohe tap. Flexi hoses are 15mm and don’t fit the 21mm (guessing it could be 22mm?) existing thread on the water feed valves. See pictures attached.

Is there an adapter I can buy?
Or do I need to replace the valve for a 15mm one? The copper pipework itself for the feeds is 15mm.

Thanks,
Ben

Ben,

You have your measurements mixed up. The chrome plated water feed valves are 15mm with 1/2” thread. Your flexi hoses are what @ShaunCorbs said are 3/8”, although they do look like 3/4” which is why @Riley said bath tap - which are usually 3/4” thread to connect to. You also haven’t said which tap you are installing (not that it really matters).

Thanks,
C.

 

[Boothus]

Thanks, I’m picking up some parts today and will report back.
Ben

 

[Jim Goodenough]

Hello,

I’m trying to fit a new Grohe tap. Flexi hoses are 15mm and don’t fit the 21mm (guessing it could be 22mm?) existing thread on the water feed valves. See pictures attached.

Every Grohe basin tap I've fitted has been 3/8".

Is there an adapter I can buy?
Or do I need to replace the valve for a 15mm one? The copper pipework itself for the feeds is 15mm.

Thanks,
Ben

View attachment 39300

View attachment 39301

 

[Boothus]

By the way the tap is a Grohe Bauedge kitchen mixer.
Side question: the flexi hoses or the bottom of the tap aren't marked for hot and cold – do I just have to take the 50/50 chance and connect & try, or am I missing something? Instructions didn't provide any further guidance
Thanks,
Ben

 

[Burger]

By the way the tap is a Grohe Bauedge kitchen mixer.
Side question: the flexi hoses or the bottom of the tap aren't marked for hot and cold – do I just have to take the 50/50 chance and connect & try, or am I missing something? Instructions didn't provide any further guidance
Thanks,
Ben

Hot usually left cold usually right.

 

[Boothus]

Hot usually left cold usually right.

fair enough, there's just no obvious left and right... I'll find out later on this evening

 

[Burger]

fair enough, there's just no obvious left and right... I'll find out later on this evening

Not even on the tap itself?

 

[Boothus]

Not even on the tap itself?

Nope, nothing to be seen.

Anyway, as promised here’s the update:

The adapter @ShaunCorbs recommended was exactly what I needed.

Fitted it all, even got the hot/cold feeds for the flexi hoses right (pure fluke), which is a miracle since whoever put the water feeds in decided they wanted to mix things up a little and put the hot on the right.

Turned the isolation valve back on and after a few second realised that one of them was leaking from the screw... tried in vain to fiddle with it but gave up and have since read that this isn’t uncommon in old isolation valves that don’t get used much.

Anyway, ended up chopping the pipe just below the old valve as I’ve got rather long flexi hoses from the tap. Was getting late so put one of those stop plugs on the pipe end and left the valve fitting for tomorrow. Enough time under the sink for one evening...