New boiler setup - hot and cold water cycles repeatedly

[muggles]

Funny you say that because why do companies (such as WorcestorBosch) and my plumber asked for how many bathrooms in the house when all the resulting suggestion can only run a single shower at a time. Anyway - I'm glad at least this is clear that I can't run two hot showers at the same time, but can this 30KW susport 1 hot shower, washing machine/dishwasher at the same time? How about underfloor heating (59m2 area), and 7 radiators? Can it do this? Or should I just replace this with my old working 37KW.

If yes, then its fine. My only regret is buying this new boiler when my 37CDi could have done this anyway after the water pressure was increased!

Yes, your dishwasher and washing machine will be cold fill only (unless your washing machine is ancient) so your boiler will have no bearing on running those.

As to your heating load, normally work on 100w / m² for UFH so you have 5.9kW, and around 7-10kW of radiators, so as a rough estimate your heating load is 16kW - your new boiler is roughly double the power you actually need for the heating side

 

[bernardgreen]

I'm talking about hot water production Bernie boy, do try to keep up, or better still butt out

Yes I know that BUTT what will happen when that boiler is having to heat just the house, what ratio of modulation can that boiler achieve ?

Even if it can achieve 10 : 1 the 5 kW would almost certainly be more than was needed and hence require the boiler to cycle ON and OFF

 

[ianmcd]

Yes I know that BUTT what will happen when that boiler is having to heat just the house, what ratio of modulation can that boiler achieve ?

Even if it can achieve 10 : 1 the 5 kW would almost certainly be more than was needed and hence require the boiler to cycle ON and OFF

as already said stick to things you actually have some knowledge of

 

[picasso]

The op is having problems with his hot water supply so probably discussions about the modulation of his boiler are not really relevant at the mo.