15 or 22mm?

[eddg]

I want to run a new cold feed from the F+E tank to the bathroom to power a mixer shower, question is do i run 15 or 22mm pipework? There is already a feed coming from the tank to another bathroom feeding another mixer shower, it starts off as 22mm and steps down to 15mm before it enters the wall................so i am now confused! Any advice gratefully received!

 

[petetheleak]

I would Run another 15mm from the tank . What you proposing to do about hot supply?

 

[Whitespirit66]

Petetheleak, seeing as you rubbished my last post and gave bad advice, can I make a suggestion to help you on this one?

You appear to have advised the OP to run their shower from the F&E tank!!!

OP - DO NOT DO THIS UNDER ANY CIRCUMSTANCES!!!

 

[seco services]

as said run a seperate pipe.

 

[eddg]

Hot supply, I was going to put a tee off from the hot supply pipe, again up in the loft that is running to the main shower. I thought i would need to do this to keep the presure right, as opposed to taking a tee off a hot supply in the bathroom? would you recommend 15mm again for this? I am not an expert plumber by any means, is the F+E tank the smaller of the 2 which supplies the CH? If so, what do you call the large tank supplying some of the cold feeds?

 

[seco services]

cws - cold water storage.

 

[eddg]

thanks seco services, i am learning slowly but surely!

 

[petetheleak]

Petetheleak, seeing as you rubbished my last post and gave bad advice, can I make a suggestion to help you on this one?

You appear to have advised the OP to run their shower from the F&E tank!!!

OP - DO NOT DO THIS UNDER ANY CIRCUMSTANCES!!![/quote
Never said take from feed and expansion Just Tank. , appreciate it we are dealing with novices but with what i can asertain the householder would appear to have already connected from F& E tank for previous shower ( hope not) but if he has would you not be better off advising him to check instead of getting upset at myself. If i have offended you son please accept my sincere appologies .

 

[eddg]

the other shower is connected from the cws, not the F+E, i realised that the small tank (F+E) suppllied the heating only, i just did not know the name for the cws, but i do now.

 

[seco services]

many people still call it an f/e or hw f/e tank.
but it was easy to understand what you meant in your post.

 

[Whitespirit66]

Petetheleak, seeing as you rubbished my last post and gave bad advice, can I make a suggestion to help you on this one?

You appear to have advised the OP to run their shower from the F&E tank!!!

OP - DO NOT DO THIS UNDER ANY CIRCUMSTANCES!!![/quote
Never said take from feed and expansion Just Tank. , appreciate it we are dealing with novices but with what i can asertain the householder would appear to have already connected from F& E tank for previous shower ( hope not) but if he has would you not be better off advising him to check instead of getting upset at myself. If i have offended you son please accept my sincere appologies .

OK Pete, fair enough. No hard feelings.

Ian

 

[Softus]

I want to run a new cold feed from the F+E tank to the bathroom to power a mixer shower, question is do i run 15 or 22mm pipework? There is already a feed coming from the tank to another bathroom feeding another mixer shower, it starts off as 22mm and steps down to 15mm before it enters the wall................so i am now confused!

Swings and roundabouts.

Leaving aside that you don't connect to the F&E, which you now realise was just a misnomer (and one that was obvious to anyone with any sense), the advantage of 22mm is less restriction to flow. If you have a long run and/or a tortuous path for the pipework then this may become important.

The second factor is the type of mixer valve. Some will not work at all well with gravity supplies, and you attempt to use them with 15mm pipework then you may get no more than a dribble.

So why would you ever use 15mm, you might wonder?

The distinct advantage of 15mm is that the hot water doesn't take as long to reach the shower. Also, if the shower supplies are pumped, then restrictive pipework downstream from the pump is less significant.

Finally, it's best to do whatever the shower manufacturer stipulates, otherwise you can't expect to get any tangible help in solving any problems that arise.

 

[Goldspoon]

I was going to put a tee off from the hot supply pipe, again up in the loft that is running to the main shower. I thought i would need to do this to keep the presure right, as opposed to taking a tee off a hot supply in the bathroom?

The pressure is determined by the head of water (distance between stored water in cws and shower head) and it does not matter where you make the connection unless there are other issues such as pipe diameter.

 

[eddg]

The run of pipework is about 4m ish, with 1 90 degree joint in it (across the loft floor and then down the wall to mixer).

I wasn't planning on putting a pump on the sytem as the other shower works fine un-pumped. Basically I was going to get a straight forward mixer shower like the other one ( i presume these are called thermostatic mixers?????). i will follow your advice softus and get the shower 1st, then i can see what they do and don't recommend, thank you.

The cws tank is at least 3 feet above the shower (not directly above it, about 3 metres away). One thing i don't undestand is the hot water is stored in a tank in the airing cupboard on the 1st floor (same floor as exisitng shower already is and new one is going - hopefully), so in other words the hot water is not above the shower head, so why does the cold have to be?

Was also a bit confused (not hard for me) when i took a look down the stud wall which the existing shower is on, cold and hot feeds come down from the loft which i can trace back and work out, but there is also a feed coming up from the floor which goes into the back of the shower, so 3 pipes in total???????

Appreciate everybodys help here, thank you

 

[scorch]

Hi all,

does the third pipe have its own connection to the shower or is it connected to one of the two pipes supplying the shower? could be someone has used the gravity supply to the shower to also connect to the toilet or other low pressure water connection.