New Bathroom

Hi
The boiler is probably not big enough to supply the water flow at the temperature you want.

If you can measure the flow rate at the shower head, and get the calculator out, you may need more Kw,s the give a good performance

Regards
Peter

 

Get your plumber back because something is wrong. The shower seems to be rated 10.5l min at 3 bar and the boiler is rated 11.5l min so all looks compatible. Should work fine.

 

Hmm, possibly, I guess.

Your boiler will possibly have a flow restrictor fitted on it's cold water inlet (that supplies your hot DHW) so that it isn't overpowered by too great a water flow through it - the installer usually makes the judgement on whether to fit this depending on what your incoming water pressure and flow is like - if it's low, say 2bar-ish - then he'd likely leave it out.

The cold feed to your shower is unrestricted, tho'. So, I guess what you suggest is possible.

Don't worry about the actual boiler being adequate - that should be fine (tho' given the choice I'd usually plump for a more powerful one simply to get max hot water whenever it's needed - like filling a bath).

The guy to call back is your shower installer. If it's a pressure issue as is likely, he will possibly just fit a PRV on the cold feed to the shower.

Or, if the water pressure is higher than say 4bar, he might suggest - for the sake of all your water systems - fitting one on the cold mains as it leaves your mains stopcock. This will then affect the whole house, hot and cold, and should help to balance it all out.

Any idea what your mains pressure is like - does the kitchen tap splash yer pants if turned on full? If you try filling a bucket from the cold kitchen tap for, say, 10 seconds, and then measure the no. of litres and multiply that by 6, that'll give us your flow rate in litres per minute.