3 Showers on Combi Boiler

[Rayment84]

Hi,

Ive got a potential customer who is asking for me to install a shower up on the 2nd floor. She already has a bathroom with shower, and a separate shower room on the 1st floor, but the whole lot will be fed by a single combi boiler (situated on 1st floor too)...my first thoughts are that the shower on 2nd floor will have little to no pressure, especially if even just one outlet is in downstairs, yet alone all! But my question is, will there be a risk of putting too much strain on the boiler if we were to go ahead with install? It's a 4yr old Worcester in there at moment but couldn't get model yet.

Any my thoughts would be massively appreciated. Many thanks in advance

 

[ShaunCorbs]

any more than one shower then you need to go unvented as combis are for one shower olny

 

[macackau]

I don't think even a worcester 42CDI could run three showers at the same time. I don't think it will place any extra strain on the boiler as the boiler can only produce a maximum flow rate of hot water given its model. I'd be after a written disclaimer signed by the customer stating that you have said the current set up simply isn't adequate for what they have planned. Couldn't you convert the boiler to work on an S-Plan on central heating to add an unvented cylinder?

 

[lame plumber]

electric shower, will also be cover for when the wb breaks down

 

[jonnyswamp]

I've got a 42 CDI and even when it worked properly (seems like a lifetime ago now) it would only run 2 showers
Go for electric or unvented and an S plan

 

[Riley]

unless you're fitting electric shower or two then Defo avoid a combi, you will not be satisfied with the end result. As said previously if you don't want electric shower then definitely look at the unvented route.

 

[townfanjon]

One shower at a time will obviously work !!

 

[Rayment84]

Thanks for all your input guys, much appreciated.

With an unvented cylinder, would then all 3 showers have hot water at mains pressure if on at the same time? Or would the same problem arise as mains cant replenish the cylinder at the rate of the hot water being used?

If customer decided to go for an electric shower in the loft with just a cold feed, surely the shower may fail to work (depending on min operating pressure) if other 2 showers are running due to demand on both hot and cold running from the mains?

 

[ShaunCorbs]

Depends what the incoming mains is but an accumulator could be installed