Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws
Grant EuroflameYou say you installed it, is this a DIY install? Different makes of boilers have different overall efficiencies, however a modern condensing oil boiler will be around 10% more efficient, however that largely relies on the system design as well.
What brand of boiler is it?
Should be able to get that 10% without trying too hard, My SE (non condensing) firebird has a flue gas temperature of ~ 330C, if I installed a condensing which I prefer to call High Efficiency (HE) boiler as they rarely condense but because of the extra heat exchanger then I would expect a flue gas temp of ~ 100C and as each 100C lower temperature results I think in around 4.5% saving then 10.5% in this case. You can obviously get lower but I think Grant specify 40/45C minimum boiler return temperature so maybe just able to achieve a little condensing benefit as the flue gases will probably be 10C higher at around 55/60C.
SJB or exedon2 might post flue gas temperatures on SE & HW oil fired boilers that they serviced.
Not sure where I picked this up but it does show a very low flue gas temperature, presume the boiler was allowed sufficient warm up time.
Reply to the thread, titled "Condensing Boiler" which is posted in Boiler Advice Forum on Plumbers Forums.
We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.