Incoming Mains Water pressure boost for whole house All aspects of plumbing questions and answers, help, tips and information

[Masterpop]

Hi,

I wondered if someone could answer a simple question for me:

Why is the Salamander Homeboost pump allowed to be installed on the incoming mains water pipe while others are not?

As far as I can see the Homeboost has the following specification:
Closed head pressure: 1.6bar; Min flow rate: 3 ltr/min; Max flow rate: 12 ltr/min

While something like Showermate Eco Shower Pump with Single Impeller Positive Head 2bar has the following specification:
Closed head pressure: 2.0 bar; Min flow rate: 0.8 ltr/min; Max flow rate: 17 ltr/min

All I see is that the Showermate is a 1/3 of the price for roughly same specification (if not "better")...
From its shape and size, it could just be a slightly modified circulating pump....

Any thoughts greatly appreciated

[proptech]

Hi.
Any pump fer this purpose has to be WRAS approved. the others you mention would not be up to the job.
Another worth looking at would be the Stuart Turner Flow~mate.
Having said that, the usual problem with low pressure is due to the pipework not being able to cope with the demands of today's requirements, with combi boilers, and mains fed supplies.
Most older installations will have 1/2 inch underground pipework, feeding 15 mm internal pipework that is expected to supply everything. It mat be better to look at your problem from that angle, rather than introducing another device that may, or may not solve it.

[Masterpop]

hi proptech,

Thanks for your reply, it much appreciated - the Stuart Turner Flow~mate looks quite interesting.

I have subsequently discovered that if you want to put a pump on the incoming mains, you are not legally allowed to draw more than 12 ltr/min. Which is why the pump manufacturers have brought out specific models, which limit the outflow.

So in theory you could still get a WRAS approved normal pump and fit a flow limiter to it - that would still work out cheaper by £100 or so - depending on what pump you bought of course.

As for your second point, you are correct - i actually still have the original lead pipe coming from the street - think it has a 28mm-30mm external diameter, though lead is pretty thick, so prob only 25 internal. Anyway, it goes into 15mm pipework for the whole house of course. The idea of the pump is really to increase the pressure in the system in general - the long 20mm plastic pipe to the back of the garden (35m) has noticeably poor pressure. I appreciate that it may not do anything for the shower or the bath, since it's the flow rate of the combi boiler that determines the speed with which the bath fills.

[proptech]

Thanks for getting back.
As for the lead pipe, it's a lot thicker than you may think, the size you mention is probably only 1/2 inch nominal bore. Also with the 15 mm copper, there will be a pressure loss for every metre length, and every bend/elbow. This can really add up.
I just wonder if it might be more sensible to replace some of this pipework, especially the lead, rather than have a device on the system that will give some degree of noise, and possible maintenance in the future.
Just my opinion !