Grundfos Homebooster - anyone experience installing? Tips?

[1456518Mike]

Hi,

Ideally I'd like to find someone who is experienced in installing these and would do work in the Surrey area. I don't suppose these are common installations for plumbers?

Failing that, I'd like to see if there's someone on this forum who is experienced in homebooster installation, and could give the benefit of their experience - what the plumber should watch out for/typical tricky bits, etc.

We have a 250ltr megaflo and the dynamic pressure from the showers is a bit under 2 bar. The booster should enable us to boost to the maximum 3 bar dynamic (limited by the PRV on the megaflo inlet).

Hope you can help!!

Mike

 

[Biggles..]

Are we alking the 200litre store pump.
It needs a preside reducing valve on the outlet,as it works like an accumulator.
Factory settings are normally quite close,set the reducing valve around 2bar.
At 10,000hours it will turn itself off and need resetting.

 

[1456518Mike]

Thanks for reply.

Why does it need a pressure reducing valve on the outlet side? The pipe will run from the homebooster to the megaflow, and on that pipe run (near the megaflow) is the pressure reducing valve that is installed on the megaflo mains inlet pipe. Isn't this existing valve enough, or do I need another one (and if so, why is that?)

It's the Grundfos Homebooster which is basically the one that's a tank the size of a washing machine that stores water, and pumps when it detects flow at a preset pressure reading.

Mike

 

[Biggles..]

It doesn't work like you think.

It charges the pipework to the pressure set.
Tap opens
Pump doesn't run again till the pressure drops below that set on the unit.
Pressure valve should be set below minimum pump setting to ensure pump doesn't keep running.
Pump runs only until pressure set on the unit is achieved.

Doesnt really give a dam about your outlet pressure.

Pressure reducing valve on pump outlet if cold draw offs are taken prior to the megaflow.

Pressure reducing valve needs to be adjustable,advise to set at 2bar.
Pump charge to 4bar and minimum to 2.5

 

[1456518Mike]

ah, ha - I think I'm getting it, but not totally sure!! I've used your numbers in the example below, to see if I've got it or not...

As water is held in the tank, there is no pressure in it. The pump charges the pipes by sucking in some water and pumping this against the PRV to 2 bar and then the pump stops - so the water in the pipe between the unit and the PRV is pressurised to 2 bar, and stands at that point.

When water draws off, the unit detects the drop off in pressure below the 2 bar it charged it to, and kicks in if the presssure going through isdetected as being less than the minimum set (2.5 bar) and pumps until pressure of 4 bar is achieved.

Is that right, or am I totally getting it wrong??

 

[Biggles..]

Pressure reducing valve works on dynamic preside,static will be higher than set value.

Basic principle is right, pump charges to 4.2 bar and stops,
Tap opens and pressure at outlet is set by the reducing valve so 2bar at outlet,
When the pressure drops to 2.5 the pump kicks in charging back to 4.2

Pressure at outlet never drops below 2bar and pump doesn't hunt or constantly run.

 

[1456518Mike]

if there's a prv on the pipe that feeds from the pump towards the megaflo, and this prv is set at 2 bar, how does pressure at greater than 2 bar get beyond this PRV? That's the bit that's confusing me. Obviously we want, say, 4 bar going out of the booster through the pipes up to the megaflow - how can this happen when a prv is on that pipe run, restricting pressure to 2 bar?

Sorry to ask you to explain it again - it's probably obvious to you, but it's hurting my brain!