Replacing gravity system; need advice

Ken_40

reasonable cost to heat such a structure. Why are you looking at changing?

The existing rads are probably oversized, so extrapolating their EDR by a multiple of 240 BTU's per SF of EDR is inaccurate to back into a boiler sizing process. You did state a heat-load calc. brings you to 75,749BTU's. Can we assume that was done via a reliable heat load calc. software; or did you use extrapolation from existing radiation or existing boiler size/rating swapping?

You must do a room by room eat-load calc. to size the boiler. Add nothing for the D/H/W and use an indirect with a mod-con if NG or LP is an option. The Roth tank is a good choice.

EAB

gravity fed heating system

I am replacing (2) 55 year old arcoliner boilers (1 with a 25yr old aero burner the other with a 8yr old beckett afg)Never a problem, always good heat; average 1100gals oil/year over past 10 years. House is insulated walls and ceiling. Calc heatloss 75,748 btuh with total radiation 168.3' (old fashion radiators) 3 story, 14.5 rooms, 2 family house in NE. 3 -5 people living here. Also replacing (2) gas DHW heaters 10+yrs. I want (1) new system heating and (1) DHW. I want what is good for our earth and for the $$. Efficient, easy to maintain, long lasting. I was born here and will be waked here, i do hope!
Suggested: (1) Buderus G215/3 oil fired bioler(up from G115/34 because of 'mixing area' in 215 but both have same mass) with Riello burner. (1)Mega Stor 53 gal indirect DHW & (1)275 gal Roth safety oil tank. 3 zones (1st apt, 2nd apt, DHW)

Ques: what kind of circulators? (given size of gravity pipes)

do we need logomatic controls or Beckett heat manager?

anything we need to be aware of in changing from gravity to pump circulated?

any other suggestions/comments? Thank you all very much.