unvented fed by pressure set.

[kimbo]

I have a customer who has problems with low pressure and continually gets airlocks. The property is fed by a reservoir on a hill which feeds a number of properties via a 2inch pipe. They have 25mm going in to their property now. Rather than sort out the plumbing pipework with the airlocks I suggested an unvented cylinder and a pressure/booster set from the incoming mains. At the moment the mains pressure is 1 bar and the property has been added to and messed around with, the main problem is the pipework and tank in the loft. By doing what I suggest I would get rid of the problem pipework and tank. The pump people assure me it is ok and I could achieve 3bar pressure. Has anyone done this and does it work ok.

 

[Nat]

Never done this but would be interested to hear how you get on of you do go ahead, mate.

 

[Destroyer2813]

By the sounds of it your talking about a acumulater tank and unvented cylinder, done it once before wernt to bad pressure after

 

[kimbo]

No its a pressure set ,the incoming main comes in to it and fills the unvented and the pump keeps going to increase pressure to 3 bar, when the pressure drops to 2 bar (when taps are opened) the pressure set kicks in and re pressurises system, the bigger the expansion vessell on the booster set the les time it will come on. It is basically a pump mounted on an expansion vessel.

 

[justlead1]

Hi. Even with a private supply pumping direct may well be a law breaker. Its general to feed a cistern first then pump from the cistern. If you intend to pump direct the low head you talk of may cause others on the 2" main to suffer negative supply, creating the ideal situation for back (assisted) syphonage. Which amonge other things is a major health hazard.

 

[kimbo]

I understand where you are coming from but The amount of water that is being pumped from the main is not significant ie it will only need to feed a bath at the most, it is only used to boost the pressure once the cylinder is full. I am aware that you would normally use a break tank if you were on normal mains. I understand that other properties which come off the mains have some sort of pump set but I am not sure what the configuration is. The suggestion was made to me by the pump supplier who cover all sorts of different solutions ie borehole pumps etc.
My only other option is to fit a break tank or extra tanks in the loft and fit a whole house set pump

I have fitted a similar setup on a farm it was a large booster set that fed 5 unvented cylinders but it was all fed from a small reservoir owned by the farm and not supplying anyone else..

 

[justlead1]

Hi Kimbo. Salesman sell the product and take the money. You are the one who gets ear ache from client. This air problem could be the result of others on the main using pumps?
If using a break cistern is can be sited at ground level.

 

[kimbo]

Justlead1 can the break tank be an ordinary header tank or has it got to be made of fibreglass.

 

[justlead1]

Hi Kimbo. The cistern will need to be sized (in my opinion) at least twice the capacity of the bath the system feeds. Needs to comply with reg's regarding fly screen, lid, insulation etc. These point are not easily achieved if the cistern is sited outside the property. There may be members on this site who have current experience simular to the job you describe, who i am sure will add to these words of mine. Good luck with the project.