It's Time To Upgrade..But I Am So Confused

northandwest

I have searched everywhere and really need some professional help (and not only with my boiler replacement).

So just moved in and we have an Oil fired Newmac NBR90V with Riello BF5 vented system with a tankless hot water heater and 2000 square foot one floor baseboard forced hot water setup.

Installed in 12/98 and is still running (OK), but we know it's time.

Heavily researched and here is my quandary..

Came from a similar setup with a 10 year old Smith oil boiler setup just like this, my son had installed a propane Navien boiler and it had to be replaced due to insides having an issue (not a 20 year system like the Newmac??) and my mother in law had replaced her hot water tankless with an electric hybrid hot water tank.

Looking at all the options, the vent issue seems to be the problem for a low cost oil solution but maybe I am not seeing one, Buderus is the boiler of choice around
here but then you need a tank instead of tankless and from a cost effective standpoint, is that the way to go (seems very high to me for my setup)?

I have looked at the heat pump / tank water heater rebates (for cost lowering) but in Mass, they no longer rebate oil appliances unless it is forced hot air.

And we live North and West of Boston, so the temps do get much colder here like -20 degrees for days on end in some years.

What would you recommend as I also do have propane tanks installed for my Generac backup generator?

Thanks,
North and West of Boston

Hot_water_fan

So you’re deciding between oil or propane boilers. You’ll find proponents of both fuel types here. Oil may work out to be cheaper overall, but a noticeable amount? Unknowable. You’d also have to have both propane and oil tanks. A positive for propane is that they make smaller propane boilers, so they can fit your house better. They can also condense, if you want a higher efficiency model. Once you do a heat loss, you can pick the right size. A well installed, right sized boiler is more important than fuel type or brand. 

Then you have a decision about domestic hot water. Hot water can be integrated with the boiler, or not. Most Americans don’t have boilers and therefore have separate systems. But if you have space, an indirect water heater connected to the boiler is a fine option - it provides high capacity with high recovery (possibly high efficiency too, depending on boiler). If you’re short on space, a combi boiler can do both DHW and central heating, but it sounds like you have sufficient space if you currently have two appliances. A separate tankless is fine too. They’re best for saving space but can have spells of being too small for your domestic hot water needs. A separate tank hot water heater is fine too - they make high efficiency propane models and the heat pump water heaters are extremely efficient too. 

Kickstand55

A wall hung propane boiler will only be good for 10-15 +/- years IF its properly serviced EVERY year with soft, mineral free Neutral pH 7+ water. It's been my experience with that, as I've replaced a number of them with cast iron direct vent boilers. Granted, the efficiency is not as good, but, you won't be replacing the boiler in a short time. Yes, separate stainless steel indirect hot water tank will be needed, and very low maintenance. It's all in the math.

hot_rod

What type of heat emitters? Is it a multiple zone system?
My experience and we see it weekly here, is 15- 20 years for mod cons that are well maintained.

The mod con will modulate well if you have multiple zones or small micro loads.

A mod con will run in the mid to high 80% even in high temperature conditions. In many cases it will reach into the 90% if it can condense for some of the season.

Its really more about how they are loaded.

Fuel cost comparison going forward is anyones guess.

www.coalpail.com has a good fuel cost spreadsheet.
Check www.dsireusa.org for any rebate programs

You can build graphs like this with weather data from your area.

Idronics 25 is another good read.
https://www.caleffi.com/sites/default/files/file/idronics_25_na.pdf