Pumped hot water mixed with cold?

[psarinuk]

Hello all

Attached are the pics from a disabled bath that I am going to remove soon.

As labelled in the pics, the hot water is pumped. Is this pump a twin impeller pump used as single? There is a vaccum switch on the bath which is used to turn the pump on, so I presume the pump won't have flow control switches (which means I cannot reuse it for my new bath without vaccum switch)?

Another thing is: Why is cold feed connected through a metal Tee to pumped hot water (second pic)? I presume there is some flow control/ balancing because as shown in the pic, the hot side only pumps out hot water to the mixer valve (HOT MIXER) and cold side only mains pressure cold(COLD MIXER).

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Thanks for your help in advance.

 

[Agile]

It seems to be a twin impeller with both sections connected in series!

Tony

 

[psarinuk]

Thanks Tony

What about the second pic, why is the cold mains T'eed off and connected to pumped hot water via another mixer valve (metal Tee)? Does it lead to better balancing if hot water is mixed with mains cold and then mixed again with mains cold at the bath if need be??

Also is it OK if I use a negative head twin impleller pump as a single (my friend has a spare one) as shown in the first pic in my new shower?

The reason for using negative head is that I've a monsoon shower that is almost the height of bathroom ceiling whereas the header tank is in the airing cupboard.

Please help ASAP.

 

[twgas]

A single pic of the whole lot may help.
The ?ed tee looks to be a blending valve.

 

[psarinuk]

Mick, Tony

Thanks for your replies.

A full pic is attached as requested. Sorry there is not much space to take a better pic.

I also think that this is a thermostatic mixer/ blending valve. They say its used to prevent scalding to the elderly and kids, but I think it is not good to fill the bath as water turns lukewarm after half bath full. Now I realise its because of this.

Since I only want to pump hot water (as I already have mains water at both bath and shower), I am confused whether I should use this or not?

Would I've any balancing issues?

Also please advise on my other question:
Is it OK if I use a negative head twin impleller pump as a single (my friend has a spare one) with one pump output connected to second pump input in my new bath + shower?

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