Hot water booster pump

Hi all, i have recently changed our taps in the bathroom to pretty mixer taps and have lost all my hot water pressure. It takes easily half an hour to fill the bath.

I have read up and it seems these taps are designed to work with mains pressure like you get from a combi boiler but we just have a normal boiler and hot water cylinder.

The cold pressure is fine as it is mains fed. The downstairs kitchen tap is ok though not as powerful as it used to be (i changed this one too to a pretty mixer).

I am looking at fitting a booster pump to increase the hot pressure but i am wondering where to fit it.

If you look at my (very rough and not to scale) diagram (which i hope you can see as i've never attached a pic on this forum before) there is a single hot water pipe that comes out the top of the cylinder and just before it goes through the ceiling into the attic it splits. The one part then goes and feeds all my taps and the split becomes the vent back into the cold water tank in the attic.

I have been reading up on various pumps and i have convinced myself that the pump should be on the floor next to the tank. Is this correct or can i put it in the attic which means that the pump would be a lot higher than the cylinder?

If next to the tank where should i take the supply from? From the vertical pipework after where the vent splits off or run it down from the attic when the pipe turns horizontal?

I hope this all makes sense and thankyou in advance,

Nick

Change the taps for a low pressure type.

Andy

It may come to that but if there's a chance that i can increase the pressure so we can keep the nice waterfall taps (which cost a bloody fortune) i would like to try the pump (which i know is also going to cost a fortune)

Bump

Your pump will need to be next to the hot water cylinder, on the floor. You'll need to do some pipework reconfiguration above the hot water cylinder to attach the vent directly to the cylinder, and take the pumped supply off the cylinder to the pump then up to the existing pipework. The best way of doing this is to install a Surrey Flange

As for pumps, buy a Stuart Turner Monsoon Extra of an appropriate pressure rating to match your cold, and put double-check valves on all the cold tap supplies

Your bathroom basin is mis-labelled as a sink, otherwise your drawing is good

abssm said:

It may come to that but if there's a chance that i can increase the pressure so we can keep the nice waterfall taps (which cost a bloody fortune) i would like to try the pump (which i know is also going to cost a fortune)

Click to expand...

Waterfall taps are not nice. Designed purely for looks, functionality not included.

If you increase the pressure on waterfall taps, what happens to the water as it exits the tap horizontally?

flameport said:

abssm said:

It may come to that but if there's a chance that i can increase the pressure so we can keep the nice waterfall taps (which cost a bloody fortune) i would like to try the pump (which i know is also going to cost a fortune)

Click to expand...

Waterfall taps are not nice. Designed purely for looks, functionality not included.

If you increase the pressure on waterfall taps, what happens to the water as it exits the tap horizontally?

Click to expand...

Don't pizz on his bonfire...the taps will be able to do that for him soon enough water should just about reach the end of the garden...

Thanks for your replies.

Drilling a hole into my hot water tank fills me with dread so i think i will just change the bath taps to low pressure ones. It is the much cheaper option anyway.

As for the water exiting the tap horizontaly, my basin isn't massive and with the cold water on full it still dosn't splash over the side so that wasn't my main concern anyway.

Thanks for your help

Edit- I just looked up the surrey flange again and i see i would not have to put another hole in my cylinder. I still think i will change the taps though.

Why not fit a Surrey Flange as I suggested? No drilling needed for that...

Yeah mate i obviously posted my edit as you were posting your reply.

If i was to go the Surrey route, i am assuming i will cut and blank off the supply to all the hot water taps and just leave the existing pipework as the vent? Then run new pipework from the Surrey to the pump, then run new pipework from the pump to where i cut the supply?

The taps i have say i need a minimum working pressure of 1 bar so i need to find a meaty enough pump for this. I have no idea what my mains pressure is.

Could you tell me why i need to match the cold pressure? If only the hot or cold tap is open at a time then one wouldn't have dominance over the other. Or is it because if the hot pressure is then made higher than the mains i would then be pushing the cold water back down the pipe and heating up the cold mains?

Sorry if i'm coming across as being a bit thick

You've got it - existing vent remains the vent, cap the old distribution pipe (the downward-facing bit of the tee) and connect your pump to the house. You've also worked out why you need to match the hot pressure to the cold pressure - you'll stop the cold coming out of mixer taps and potentially force hot water into the mains if you have a big mismatch. This is also why you need to fit non-return valves to the cold - in the event that the hot does overpower the cold, the valves will close and prevent hot being forced into the cold supply.

This will do the job nicely and they sell this which should be a suitable flange

Many many thanks for your help and advice. I'm just off to find out how to find out how to measure my mains pressure then i'll go and spend some (more) money

It might be worth looking at having an unvented cylinder installed, modern taps work better with equal pressures and its going to be a better system than having a noisy pump running.