Water pressure

[AnitaB]

Hi I would welcome some advice. I'd like to be able to run baths and showers simultaneously without loss of pressure (2 at any time). There is currently a combi boiler in the property, would it be more cost effective to install shower pumps, switch the boiler to a condenser type, or can you recommend another way to improve pressure? Has anyone had experience of external pumps and wells that can be installed at the mains supply?

Other than an expensive Megaflow system, can anyone recommend a less pricey version on par with performance?

Many thanks for your advice. Anita

 

[Dan Robinson]

Champagne Ideas. Beer money.


Combi will never run two decent showers at the same time. You can't directly pump the mains beyond 12 litres per minute.

Your cheapest option maybe two crappy electric showers.

 

[AnitaB]

Hi Dan, champagne ideas, beer money exactly LOL! I will pass this on to my client. I would never ever propose ugly bugly electric showers unless Philippe Stark designed one. Mega flow it is then. Many thanks for your super quick reply.

 

[Dan Robinson]

Megaflows are not the best out there. But the performance is governed by the supply to the building.

You might well find that unless the water main is upgraded the Unvented cylinder is no better than the combi.

 

[AnitaB]

So what would you do?

 

[Dan Robinson]

Carry out the tests that have been described in countless similar threads like this one to see what is viable.

You're looking for dynamic flow and pressure around the 25 litres per minute and 2 bar respectively.

 

[Charnwood]

If only 2 outlets are to be used at once, check the flow rates to baths and showers, divide the lower rate by 2 and fit flow restrictors to match that figure. Obviously, performance will be impaired.

Then again some t0sser might turn the kitchen tap on.

How many baths/showers does your client have?

 

[AnitaB]

Dan: I understood that's what you meant in first response, sorry, let me clarify, once I've had the flow rate checked...

Problem = Low pressure when taking showers simultaneously
Solution = check flow rate and install standard boiler with shower pumps?

Charnwood: Client has two bathrooms in a 1930's 3 bed house, she has taken on a lodger to supplement her beer money budget and champagne ideas (i.e. calling me to help with space planning and interior design), the lodger takes a shower in the morning when she does, they'd have to have very long arms to turn the tap on in the kitchen while they're in the shower, so no problem there. Call me an idiot, I think there is something I didn't quite understand in your explanation of restricting flow, I'm trying to improve the water pressure, not obviously impede the performance, please clarify...

Many thanks both of you.

 

[Dan Robinson]

The pressure stays the same - it is just being split two ways when they run two outlets at the same time.

Combi's can only pass a limited amount of usable hot water - that amount depends on the kW's the boiler is rated to.

If the customer's water main is only bringing in say 15 litres per minute, there is no point fitting anything other than a combi unless they are prepared to spend money on tanks/pumps/accumulators.

A 1930's 3 bed house in London might not have the space?

 

[Charnwood]

Call me an idiot, I think there is something I didn't quite understand in your explanation of restricting flow, I'm trying to improve the water pressure, not obviously impede the performance, please clarify...

You can't improve the pressure unless you fit a pump restricted to 12 lpm (Salamander do one, I think - champagne money, though.).

My 'solution' would just ensure there was no fluctuation in flow rate at the first shower to be turned on when the second shower was turned on.

 

[AnitaB]

Dan: I did wonder where a megaflow cylinder might fit in, there is space, but it could be used more effectively. I will do as you recommend and have the mains flow rate checked before making any decisions. Should I call Thames Water in to do this because it relates to the mains or a private plumbing contractor?

Charnwood: Ahhh I see what you mean!

Many thanks again for the very helpful information.

 

[Dan Robinson]

You'll need a privater plumber.

Depending on age and model, the boiler MAY be able to be used to feed the cylinder; but honestly, when she/you start seeing the figures coming back a change in showering habits might well be better.

As Charnwood mentioned flow restrictors on showerheads may do jut enough. But if I were paying rent I wouldn't want my services reduced.

 

[Charnwood]

if I were paying rent I wouldn't want my services reduced.

But he gets that everytime Anita turns her shower on.