Can you do this?

[Nostrum]

You'll need a new cold feed from cwst to shower through a twin impeller pump I reckon. Happy to be proven wrong mind.

 

[rocketmanbkk]

Nostrum, that was my thought also.

So if I did that, had a double impeller pump could I then include just the hot for the taps?

 

[rocketmanbkk]

What about the size of the cold storage? What would be correct?

 

[rocketmanbkk]

I want to tell her the correct way even if its a price shock for her.

I won't bodge and I want it to last.

 

[Whyme]

you will probably have to up size the tank to cope, there are calcs but couldnt tell ya off hand. going back to cold mains and pumped hot just looked at salamander mi's and theres a picture of just that as ok as far as i can see. very confusing.

 

[rocketmanbkk]

I appreciate all the comments.

It'll be easier if I can use a single impeller as the cold pressure is fine.

This will also save custard money in materials. & labour .

 

[Nostrum]

Nothing to stop you including the hot taps through the pump. More likely is the new taps aren't suitable for low pressure installation.

Just remember every time you run the tap the pump will start so noisy and the pumps going to want to be a quality one if its to last more than a couple of years.

Not sure on CWST sizing, there are calcs but I would just suck it and see if its a reasonable size. Replacing for a larger tank retrospectively won't cost the earth anyway.

 

[Nostrum]

you will probably have to up size the tank to cope, there are calcs but couldnt tell ya off hand. going back to cold mains and pumped hot just looked at salamander mi's and theres a picture of just that as ok as far as i can see. very confusing.

Does it show them terminating at a mixer?

Also, you'll have unbalanced feeds more then likely?

 

[Whyme]

oh forgot to say the nrv is usually on the hot to stop mains firing up the hot when the pumps not on, if the pump hasnt got one.

 

[Whyme]

Does it show them terminating at a mixer?

Also, you'll have unbalanced feeds more then likely?

looks like one on the pic but it is a drawing. and have just got a nrv on the hot..

 

[Nostrum]

Which pump model is it? Or if you have a link to it even better!

 

[Whyme]

Install Single Shower Pump. think thats how you post a link.:thinking:

 

[Nostrum]

Certainly looks like it!

 

[rocketmanbkk]

I'm looking at a I stall guide too. Looks ok for mains feed with single impeller. Nrv is needed on hot supply after pump. Also full bore valves after pump for hot and also put one on cold. I'll need to fit a surrey flange also. I may also need to fit an anti gravity loop as the pump may need to sit at a level just above the tank. I think if I get a good size pump I can do it in 22mm to taps.

When I go up to shower it needs to go in 15mm.

Can I just put a reducing fitting on (22-15) or should I also put a prv on?

I think with your help I've got it sussed (well to price anyway).

 

[rocketmanbkk]

So, what size pump?

 

[IDCHAPPY]

So, what size pump?

Pressure wise? I'd be wanting to fit at least a 2.5 bar one to be honest, could then cope better if more than one outlet is opened 🙂

 

[rocketmanbkk]

Salamander? As it's got a plug.

 

[rocketmanbkk]

Maybe a salamander RGP 120 3.6barp

 

[rocketmanbkk]

Maybe RGP80 2.4 bar

 

[Ermintrude]

Get
http://bit.ly/1fzh6us

75l wras cws for cold headder. You need to have a balanced hot and cold. Mains into pump won't work and a prv is pointless as the pump increases pressure and then the prv reduces it. 15mm on a shower fine. Just make sure incoming to pump 22mm on both hot and cold. No need for ISo after pump u want them before. Mfr normally has them on the hoses