Plumbing

Low flow rate with unvented direct cylinder

Anonymous user 23/02/2024 - 3.54 PM

I have an unvented direct cylinder in a 4 bed house where our pressure in is between 2-2.5 bars. We have 2 new bathrooms fitted but the flow rate is shocking. We get around 6 litres per minute flow in each bathroom but the shower head data sheets suggest we should get at least 10+ at 2 bar pressure We have a 15mm copper pipe from the cold mains which goes into 22mm before going to the bathrooms. We have 22mm for hot. It feels like the cold water flow is the main issue. Sometimes the flow will be much faster when we first time on the shower and then it goes down. What is the issue here? We’ve had a suggestion to fit a pump or to upgrade the cold feed to 20mm but we’re not sure what to do. EDIT: The issue of low flow has always been a problem, before getting the new bathrooms we had a gravity fed system To clarify we have 22mm going into the house into the kitchen cupboard, it then goes down to 15mm when it gets to the house. Then it goes to the water tank and from the water tank it goes to 22mm. I think the issue is we need 22mm throughout the property