Shower in between hot water and cold water tank levels, which type of shower pump do I need?

MuffinsDa · 02-10-2022 4:35pm #1

I live in a 3 storey house and embarking on renovating a bathroom on the top floor. It currently has a shower that's neither pumped nor electric so very low pressure.

I'm wondering if I can install a shower pump for it. The cold water tank is in the attic so above the shower, but the hot water cylinder is in 1st floor (below the shower). I was reading about different types (positive and negative pressure) and it seems to depend on whether your shower is above to below the tank but what would apply in this case? I'm kinda stuck in-between!

Sleeper12 · 02-10-2022 8:30pm

The water for your hot water cylinder comes from the cold water tank in the attic. So regardless of where your hot water cylinder is, both your hot and cold will have equal pressure. It sounds like you won't need a negative head pump

MuffinsDa · 02-10-2022 8:39pm

that's right. I was kinda baffled by how I get water pressure on the hot tap on this floor. That explains it!

Magilla Gorilla · 02-10-2022 8:48pm

I’m upgrading an upstairs shower room. Removing electric shower and putting in rain shower fed from cylinder. The cylinder is downstairs. Plumber has fitted a negative head pump beside the cylinder and has run the supply back upstairs to the new shower. Simply not enough pressure for it to work otherwise.

MuffinsDa · 02-10-2022 9:19pm

I saw a YouTube video from a UK plumbing crowd that said if you get 1l/min flow it should be enough for a positive head pump. Did you have even less than that?

Magilla Gorilla · 02-10-2022 11:20pm

I think I saw something similar. We even measured it with a jug. 😀 Within the spec, but no way a bigger shower head would work without the boost I think. I’m not an expert but I think you’ll need a pump. Maybe you could try without and fit later if it doesn’t mess with your build. I may well need a bigger cylinder but plumber suggested trying it out as is for the moment. Waiting on a tiler so can’t report any practical experience yet.

Sleeper12 · 03-10-2022 12:28pm

A negative head pump is required when bottom of the cold water tank in the attic is lower or only a few inches higher than the shower. If the shower is on 1st floor and cold water tank in the attic above it then positive head pump is all that is required

Shower in between hot water and cold water tank levels, which type of shower pump do I need?

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