Plumbing

How would you boost the flow from an unvented cylinder?

Anonymous user 01/03/2024 - 2.57 PM

Hi All, I would really appreciate your help – having a bit of a nightmare with our local plumber. We recently installed a very expensive unvented hot water cylinder and system boiler to achieve the best possible flow to our shower. It replaced a gravity fed system with a 3 bar shower pump, which gave us excellent pressure. My plumber said that the cylinder would give us 4 bar, so slightly better (although after the install he then said it's maximum capacity was 3, then admitted that I would still need a pump as the static pressure in the area wasn't good enough). We didn't install a combi as he said the incoming mains pressure wasn't good enough to give us a decent shower. Incoming mains outside the house is 2 bar, which drops to 1.7 fully open. We've checked that there are no leaks or anything that might reduce the flow inside the house. Flow rate on the kitchen tap before we installed the cylinder was 8 lpm, which my plumber said would be sufficient due to the accumulation of pressure inside the cylinder. I have since learned that they didn't actually test the static pressure only the flow on the kitchen tap. Shower pressure is rubbish – significantly less that we had with the old system and drops off a cliff every time you flush the toilet or open a tap. - What are our options to bring the pressure back up to 3 bar? - Would you install something like a Salamander accumulator ? - Would you just suck it up, learn the lesson and pay what it costs, or try and recover the money from the installer? Any advice would be greatly appreciated. Thank you. Ben