Improving HW pressure in a gravity fed (positive head) system

[rjsdavis]

Hello to all

We have a pretty standard family home, with a pretty standard gravity-fed system. Cold tank in the loft. HW tank in the airing cupboard. The system works, and works ok. It is a positive head system.

We have two bathrooms, and the HW supply to the taps/gravity shower in both is ok, but not amazing. It’s certainly usable, and we’ve used it quite happily for the past 20 or so years. The HW pressure in the downstairs kitchen is weaker. As far as I can tell, the cold water supply to the downstairs sinks is mains, and the cold supply to the upstairs sinks and showers/baths is gravity from the loft-tank.

We’re going to completely refurb a bathroom shortly, add in Hive and some other jobs, so now seems a good time to improve the overall system if I can. I am absolutely not interested in conversion to an unvented, pressurised system, no matter what the potential benefits or costs. I simply want to increase HW pressure to the upstairs showers (which are in baths – not standalone showers) and kitchen tap if possible and reasonably practical. The pressure in the kitchen tap is certainly usable, but I’d like to increase it for two reasons;

1 – So that it is closer to the cold pressure
2 – So that we can use high pressure designated taps in the kitchen/utility rooms if we wanted to – at the moment, we’re restricted to low pressure taps.

Therefore, looking at several potential products to solve the problem, but would very much appreciate any expertise? I've also been reading this thread here:

https://www.diynot.com/diy/threads/...t-water-pressure-to-taps.438538/#post-3424176

It appears that I should be considering:

• 46497 Stuart Turner Monsoon Standard 2.0 Bar Single Pump (Positive head)

• Grundfos UPA 15-90N (160) Domestic Home Booster 240V

• ShowerPowerBooster

Many thanks

 

[Mr.B]

Others will be more helpful but I would just say my neighbour has a similar system to yours and was happy with her (rather average) shower performance - but when she moved out and put tenants in one of the things she was asked to do was provide a better shower.

She had a contractor fit a substantial Stuart Turner pump to the hot water outlet and it improved the shower no end.

However - two things ... it is rather noisy (it's in the airing cupboard, next to the cylinder) ... and a week or so after it was fitted I noticed the contractor was back to fit a new hot water cylinder. So presumably in fitting the pump the fitter must have disturbed a weld on the cylinder. So maybe be aware of those two considerations.

 

[muggles]

You can pump off your hot water cylinder, just be aware that it will run out faster. I'd recommend spending the extra £26 over the 2.0 bar pump and getting the 4.5 bar. With all these pumps, their rating is a theoretical maximum at zero flow rate, and pressure drops off the more outlets that are opened. As you're supplying your entire house, you should go for the more powerful pump to ensure you don't get the drop-off. You can always fit a pressure reducing valve to limit the maximum pressure without affecting the total flow rate. Bella Bathrooms are the cheapest supplier usually, and very helpful too.

If your cold outlets are tank-fed, you'll either need to convert them to mains (easy enough to do) or pump those as well