Flow and return temperatures for LPG consening boiler

[shraheens]

I have gone through a lot of vokera valiant raven heat etc… websites and I maybe I have missed it but I just couldn’t find anything regarding flow and return temps for condensing LPG boilers

At the moment I'm sizing radiators up my new house, I just wanted to know the flow and return temperatures of these boilers. I'm have got conflicting temperatures of 60oC flow and 40oC and also 50oC and 39oC, so really I'm neither right or wrong on that subject so on the condensing side off things

what is to be considered the optimum temp since it is condensing its important to get this correct especially on the sizing of the boiler, so I hope anyone can give me help on that one!

Also the LPG connection is going to be copper so if ½ is fed from the LPG tank wouldn’t that be plenty for to feed a 9.0kw to 26.6kw boiler.

Finally what is the best condensing boiler out there I hear and know of a few vokera out there, my installer thinks that there bullet proof but I have heard of a lot of heat exchangers failing? (Maybe there bullet proof cheap for him!!!) so I have looked at the Valliant a lot I email every one of these companies in the last week and only a day passed keston replied, as of yet no one else has replied, maybe I should go with keston !??

Any how any one with better experiences let me know, because I certainly don’t know and that what this forum is for!!!

I would like to thank you for all your time and effort and a lot of patience for reading this,

Thanks again everyone