flow rate for combi's

[JPC]

greetings...

whats the minimum flow and pressure required from the mains to run a combi to be used in a 7 rad 1 shower and 1 large bath bungalow.

My mate (the corgi puppy) tells me as long as you are getting about 2bar pressure (to fill the c/h side ?) and what ever the boiler specifies as a dhw flow rate....so say min 10 l/m ?

is that correct ? (although i know it will perform badly filling bath etc)

NB - i have tried to tell the cutomer to stick with their vented system and just get a new boiler and updated controls etc but they want the space taken up by the hwc.
thx

jamie

 

[corgiman]

As I guess if you have a 24Kw combi they are looking for about 11 lpm

I would say that the supply is inadequate for a combi and they will hate it if one goes in

 

[JPC]

yes i estimated a 80000 btu, so is the mains got to be at least 11 l/m then ?, to be able to deliver 11 l/m of hot water

what about the pressure..whats the minimum on the mains to be able to operate a combi (i assume at least 1.5 to fill the ch)

 

[corgiman]

could be wrong but dont think there is a minimum.#


still say the delivery of the mains at your job is too low and a combi would be out of the question