N
n141311
would think if you wanted the re heat times as you stated with heating on the same time 100 kw is what you want, if your happy with a slightly longer re heat time (approx 20 mins more 80kw sounds about right)
rinnais are very good and can handle the load but its more cost (alot more) esp if you have already bought the cylinders but agree with his pressure/flow thoughts as hes on site
dont agree it will limit hot water temp, under sizing will only limit flow rate and esp if you havent got a secondary return it will add to the water draw off before it hot
you have two options (one you might not like)
one try and get as close as you can and re pipe in correct size (and hope its enough)
two re pipe the lot and either put the costs onto the inexperienced plumber for any damage to the walls / finish
best option is normally the worst sorry to say
sorry i couldn't be of more assistance
Hi Shaun,
Cylinders and boilers haven't been purchased yet.
What are the pros / cons of the Remmai solution vs unvented cylinders in your opinion? I'm concerned about the 3 things: instant hot water, delivered high pressure, in a cost efficient manner so I don't get killed by running costs
Appreciate your experience mate.