Is this idea feasible?

[Useroftheforce]

The hot water pressure in the house is not brilliant and I was thinking about installing a pressurised hot water cylinder. Our mains pressure is stonking!

The hot tank is fed by the header tank as usual. This would obviously be straight conversion – no problem.
What makes it more tricky is that there is a shower pump that feeds from the header tank for cold and the hot tank for hot. In other words the header tank is emptied twice as fast when the shower pump is running.

The obvious way I can think of doing this is to leave the header tank in situ. As is and have that feed just the shower pump cold. Trouble is once the ball cock on the header tank opens to replenish I suspect that would lower the pressure into the hot tank too much to allow reasonable flow for the shower pump from the mains.

All the feeds to the hot tank and shower pump are 22mm. The only run of 15mm is to the header tank from the mains inlet.

I know this has to be fitted professionally BTW before the regulation police see fit to be boring and shout.

 

[Razor900]

I know this has to be fitted professionally BTW before the regulation police see fit to be boring and shout.

Strange way to ask for help

If the mains pressure and flow is that good you would have an unvented cylinder with a balanced cold water take off, all supplies would be at a good pressure and there would be no need for the shower pump.

You need to measure the amount of water that comes out the kitchen cold tap or outside tap 3 or 4 times during the day. If you average over 25 litres a minute you could be in business

 

[Useroftheforce]

Thanks for the response that's lovely.

 

[doitall]

I suspect that would lower the pressure into the hot tank too much to allow reasonable flow for the shower pump from the mains.

You don't really mean you have a pump on the mains do you.

 

[Razor900]

there is a shower pump that feeds from the header tank for cold and the hot tank for hot. In other words the header tank is emptied twice as fast when the shower pump is running.

.

 

[bengasman]

Unvented cylinder fed by 15 mm, and the cold will probably come from the same feed, that could be interesting.