Is Shower Power Booster Pump from plumhq the only solution?

Tonyhackney · May 14, 2025

Hi guys I ambuilding 2 ensuite bathrooms next to each other in my house with 9.5kw electric showers. The pressure isn't more than 2 bar and will have sinks and toilets in both ensuite. When people open the tap on one floor it aready affect the pressure on other floors but luckily I use megaflo on other floors.
I have looked around and it seems that there are negative head pumps that simply increase the pressure for the all house or flat but here what I need is something that only helps those 2 electric showers so that people don't get burnt if someone else opens a tap anywhere in the house. If lucky the shower will stop automatically if not enough pressure but that's not convenient at all for whoever is having a shower as they won't know what's going on...
I have seen this Shower booster pump which was a Dragon's den succes and doesn't seem to have competitors. Would this be good enough if the two showers are working together at the same time suddenly.
How many years do they last, is it better to change them every 3 years rather than waiting for a bad surprise?
Are they other equipment that could help around the house such as tap low limiters, particular toilet flushes taking longer to fill, etc... to help the loss of pressure???
Thank you ever so much guys.
Tony

John.g · May 14, 2025

I have never seen a proper pump curve for the "Shower Power Booster Pump" which at 12 watts won't produce a awful lot of boost, one per shower might be OK but very doubtful IMO if one will serve two showers. Grundfos/Salmander or other makers do make mains booster pumps but for around the same money you could consider installing a integrally pumped shower(s) like a Trident T80 SR which is normally fed from a (the) CWSC but can be fed from the mains via a PRV (pressure reducing valve) set to ~ 0.5bar, this invalidates the warranty but I have seen a number of this type of installation thats worked fine for years.

Chuck · May 15, 2025

In cases where a shower is being starved of flow when taps, etc. are being used elsewhere in the building, pressure boosting pumps are not likely to fix the problem. First, the supply (service pipe) to the building needs to be checked to make sure that it can supply adequate flow and (dynamic pressure). If that's not the problem, the pipework inside the building needs to be improved by increasing the size of the flow-limiting section(s).

Shower pumps work best where you have a good sized tank of water, but not enough head (pressure) to drive the water through the shower. They are disappointing in cases where the pipework feeding them is the limiting factor.

You need quite a beefy electricity supply (80A) to run two 9.5kW showers at the same time. Make sure a qualified electrician checks the wiring and signs-off the installation.

John.g · May 15, 2025

I have never seen two electric showers installed in a way that both can run together due to the above power limitation, they are installed either in Priority or Non Priority mode. Either mode means only one shower can run at any one time, Priority means that one particular shower will remain running if the other is requested or if the other one is running then the prioritised one will take over and run if requested and the non prioritised one will trip.
Non Priority mode means the first one running remains running.

Tonyhackney · May 16, 2025

John.g said:
I have never seen two electric showers installed in a way that both can run together due to the above power limitation, they are installed either in Priority or Non Priority mode. Either mode means only one shower can run at any one time, Priority means that one particular shower will remain running if the other is requested or if the other one is running then the prioritised one will take over and run if requested and the non prioritised one will trip.
Non Priority mode means the first one running remains running.

Hi Guys, both showers have their own 10mm2 cable, Rcd' setc... The problem and the question is about water pressure. I think that my only solution is a 25-gallon cold water tank with 2 outlets and two pumps so isolated from mains pressure.

John.g · May 16, 2025

Nevertheless, running 2 X 230V 9.5kW showers together requires 82.6A so a minimum 19.0 kVA house supply, have you got this?.

Tonyhackney · May 16, 2025

John.g said:
Nevertheless, running 2 X 230V 9.5kW showers together requires 82.6A so a minimum 19.0 kVA house supply, have you got this?.

I'll doublecheck but should be fine thanks as 4 storeys 10 bedroom. Thanks anyway any advice is welcome.

Tonyhackney · May 16, 2025

Chuck said:
In cases where a shower is being starved of flow when taps, etc. are being used elsewhere in the building, pressure boosting pumps are not likely to fix the problem. First, the supply (service pipe) to the building needs to be checked to make sure that it can supply adequate flow and (dynamic pressure). If that's not the problem, the pipework inside the building needs to be improved by increasing the size of the flow-limiting section(s).

Shower pumps work best where you have a good sized tank of water, but not enough head (pressure) to drive the water through the shower. They are disappointing in cases where the pipework feeding them is the limiting factor.

You need quite a beefy electricity supply (80A) to run two 9.5kW showers at the same time. Make sure a qualified electrician checks the wiring and signs-off the installation.

I've decided to have one shower on megaflo with shower mixer and the other from cold mains with an added small shower power booster that would go on only if needed automatically. I just need a good shower mixer that works well at compensating hot and cold fluctuations. Feel free to advise on that. Thanks. Tony

ShaunCorbs · May 17, 2025

Why not just design the system properly eg boost the mains of water board / supplier can’t do anything there end

Eg dab easy system or a scuba tank etc