Secondary Hot Water Return on Pumped Shower supply.

[Markpoint]

New Shower being installed - thermo mixer - new shower is around 60 feet from HW cyclinder, multiple swept 90 deg bends plus around 10 feet of vertical rise, so negative head - 22mm pipe is installed (15mm last 1 meter) - without pump - dribble so intend fitting dedicated Salmander 3 bar pump with cold mains stepped down to 2-3 bar to equalise.

Owner wants a hot water return to minimise hot water waiting time.
There is 15mm pipework in place but not connected anywhere.

Can't see how I can fit a HW return to a dedicated 3 bar pumped supply.
My thinking is a 3 bar supply would not take long to flow to the shower head.

Any ideas??

 

[Welder]

You need to think this through. What happens to the pump when you install this return?

 

[Markpoint]

Hi Dave, pump will sense flow and kick in taking the whole HW 22mm and return up to 3 bar back into HW cylinder. So my thinking is it cant be done unless someone has a bright idea or find a single pump that has a timer to run as a secondary return pump for say 30 mins before use, shutdown or autosense shower or basin use and then kick in again as at 3 bar to provide the required shower pressure.

 

[Welder]

It's a non starter. The only time you'd use a return like that is on an HP system such as an UVC.

 

[Markpoint]

Thanks Dave..