3 showers at same time?

[WPB]

I have a 5 bed house with a 5 yr old Baxi Combi 105e boiler that feeds the radiators and hot water.
Main bathroom has a Mira Sport Max Electric shower - no problem
Two en-suites have Aqualisa Quartz showers fed from the boiler.
What do I need to do in order that any one can use the showers at the same time and have hot water.
I have had so many different answers.
Water board have checked supply and we have a flow rate of 14ltr per min and 2.5 Bar Pressure to the house. A new mains pipe was laid to house 5 yrs ago when extension was built.

 

[WHPES]

If you are struggling for enough hot water at the moment, the simplest and cheapest thing to try first is to put flow restrictors in the hot and cold supplies to the mixers fed off the boilers. THese are little plastic things which go in the pipework and reduce the flow rates.

 

[WPB]

Not being too knowledgable how does this help?

 

[Plumbstar Tom]

what hot water system are you on?

Gravity, unvented etc?

 

[WPB]

Direct mains water to combi. No tank.

 

[Plumbstar Tom]

i prehaps should have read the thread, my bad

tough on a combi system

Try the flow limiters mentioned above

 

[WHPES]

I presume you already have PRVs fitted to hot and cold feeds to the 2 showers fed from the combi?

 

[WPB]

My knowledge is limited. The Aqualisa's have a processing box up in the loft space above?

 

[WHPES]

Get a pro

 

[Toddyplumb]

You boiler will only give 12.7 litres/min at 35 degree rise. You could try restrictors but you are always going to struggle with multiple draw offs and a combi.
Unvented cylinder

 

[Gray0689]

Toddyplumb is right change to unvented
A combi is for a flat not a house

 

[Spudhater]

Why are Combis only for flats and can you still get Le Blancs

 

[Gray0689]

In my opinion combis can't produce enough hot water for multiple draw off points not enough volume

 

[Spudhater]

WB 550 CDI High Flow Combi can deliver 25L/min @35degree rise

 

[justlead1]

Hi. Try shower rose with finer holes. You will still shower but use less water.

 

[oldplumber]

worst case scenario if you must run 2 showers at once, replace one for anther electric or add an unvented cylinder to be heated off combi primaries and leave kitchen and one bathroom on the cobi hw supply and then repipe other bathrooms to the unvented cylinder, then happy all round, need an s/y plan set up andsome changes to combi programmer/wiring for it to work ok

 

[Dannypipe]

Once again, Oldplumber is spot on. I have done exactly what he suggests. It works a treat.

As in run an unvented, heated from the primary side.

It was years ago, and my father wired it up, not me. They were seriously chuffed with the result.

 

[oldplumber]

oops heads to big to get out the door now, im not that good, just use common sense when im awake, which is as little as possible

 

[WPB]

I am grateful for help so far. I have called 5 plumbers, 2 never even came back to me, 1 looked and said I needed a tank(think it had another name) commanly used on the continent that has a diaphram that pushes the pressure up but never came back to me despite 2 calls, one has said a cold water tank & immersion and last one said too reduce the water coming into the Aqulisa processors by turning the valves on the cold and hot inlets a little. This last one suggestion seems to work when you turn both Aqualisa's on they produce a flow of hot water. Excuse my ignorance but is this what you are meaing by the prv's. I have sought professional plumbers and been utterly bamboozled by the array of different answers and just trying to understand.
Will reducing the water into the Aqualisa's be a problem?
I am grateful for your advise guy's.