Top floor Flat - Mains Booster advice

[Andre_P]

Hi All,

I have a GrundFos Home Booster, the 3.5bar version which has transformed my flat, its used for every tap aside from the kitchen cold tap and the kitchen white goods that need mains, it also supplies the pressure for my combi boiler that is the hot water and central heating system.
I found that when there are multiple people using the water the GrundFos tank empties fairly quickly because the mains pressure here is terrible. We're in an old Georgian house converted into 7 flats, I'm on the third floor.

My question is what mains pump can I install that will boost the mains pressure so that the GrundFos will not suffer from an emptying tank when the demand for hot water is high. Becuase I have a combi boiler it means in theory I could run hot water endlessly, i'd like to boost the mains so this is possible. Do i have to avoid boosting the cold water for the kitchen cold tap? Shall i boost just the inlet to the GrundFos tank? shall i boost the mains into the flat? Im not sure what i should do nor do i know what would be the best pump option. Something not too loud but powerful and reliable

I'd appreciate any advice

Thanks

 

[Chuck]

I think that what you are suggesting is not going to solve the problem. Your options are to either increase the size of the tank, reduce the rate of consumption, e.g. by fitting eco shower heads, etc. or increase the capacity of the service pipe that fills your tank.

 

[steadyon]

1. You are not allowed to pump the mains, or at least, not more than 12 litres per minute.
2. If you were to pump it, you would probably starve the downstairs flats of water.
3. Chuck's ideas are right.
3a. However, increasing the size of your tank only helps if the larger tank is:
i. Large enough to satisfy your needs.
ii. Can fill during the times your neighbours are not using their water.
3b. Reducing the rate of consumption speaks for itself.
3c. Increasing the capacity of the service pipe which fills your tank should help, but, depending on how the building is arranged, should also help you neighbours. Might be a common interest for all leaseholders, and possibly a cost sharing exercise.
4. You might also want to check your lease. Many do not allow the installation of combi boilers.

 

[Marc Bowers]

Did Chuck mean to increase the supply pipe size or by capacity was he suggesting an accumulator.

 

[Scott_D]

Is it a shared supply or do you each have a stop tap?
Is your fully open?
Have you got loft space for a storage tank?

 

[Andre_P]

Is it a shared supply or do you each have a stop tap?
Is your fully open?
Have you got loft space for a storage tank?

Its not a shared supply, we each have stop taps and water meters.
Yes mine is certainly fully open
Yes I have loft space which is where I have the combi and the GrundFos

 

[Scott_D]

Can you tag another tank or 2 onto what you have so there is plenty of stored water?

 

[Andre_P]

Can you tag another tank or 2 onto what you have so there is plenty of stored water?

This is certainly possible, there is space, provided the beams can hold the weight.
How would the extra tank feed the Grundfos pumped tank? Wouldn't I need another pump?

 

[Andre_P]

1. You are not allowed to pump the mains, or at least, not more than 12 litres per minute.
2. If you were to pump it, you would probably starve the downstairs flats of water.
3. Chuck's ideas are right.
3a. However, increasing the size of your tank only helps if the larger tank is:
i. Large enough to satisfy your needs.
ii. Can fill during the times your neighbours are not using their water.
3b. Reducing the rate of consumption speaks for itself.
3c. Increasing the capacity of the service pipe which fills your tank should help, but, depending on how the building is arranged, should also help you neighbours. Might be a common interest for all leaseholders, and possibly a cost sharing exercise.
4. You might also want to check your lease. Many do not allow the installation of combi boilers.

12 litres per minute would be leaps and bounds better than what it currently refills at

I can discuss increasing the size of the main service pipe to the building from the road supply, this does involve some significant ground works though and I'd prefer to avoid it

 

[Andre_P]

Can you tag another tank or 2 onto what you have so there is plenty of stored water?

do you mean something like this?

Grundfos Home Booster 180L Slave / Spare Water Tank

Buy Grundfos Home Booster 180L Slave / Spare Water Tank Online at Anchor Pumps, Find the Best Price Anywhere Online, With Free Delivery.

www.anchorpumps.com

 

[ShaunCorbs]

Yes

 

[Chuck]

Did Chuck mean to increase the supply pipe size or by capacity was he suggesting an accumulator.

The former. Accumulators have their uses but I think of them as a measure of last resort.

 

[Andre_P]

Yes

OK I found the installation instructions here

https://www.pumpsalesdirect.co.uk/pub/media/data_sheets/grundfos-home-booster-data-sheet.pdf

I understand how slave tank supports the primary pumped tank.

I'll also explore the mains pump keeping the limit to 12l/m.

Thanks for everyone's advice.

I have another question. While the tank fills, there's this pipe noise, like a moaning sound as the tank fills. I think it's noise from the water flow through the pipe, is this normal and can anything be done about it?

 

[Marc Bowers]

The former. Accumulators have their uses but I think of them as a measure of last resort.

Agreed but if you can’t change the supply pipework and can only break into the potable supply, it can have advantages over a mains pump.