Boiler help? Over my head here…
My situation: Central MA (Zone 5A), 800sq’ Cape (recent wall blown insulation), walk up attic (recent 16 inches blown insulation), unheated basement, 1 bathroom, HE washer, dishwasher, 2 adults, 1 child. Currently running on gas with a 60% efficiency (96k BTU oil boiler converted to gas).
I’ve gotten a few (too many?) quotes and everyone is offering something different. I’ve read through a bunch of threads and you guys have been super helpful, but I’m having a hard time relating everything to my own situation.
These are the four most common setups I have been proposed:
1) Lochnivar 199k combi unit (4.8gpm)
2) HTP Pioneer 100k with HTP 45g indirect
3) Laars Mascot 199k combi unit (4.8gpm)
4) Lochnivar 150k boiler with HTP Superstor 40g indirect
Combi proposals have all been 1-2k cheaper than indirect options but I worry about what I have read about their reliability and that they don’t mesh well with the slow draw of HE washers and dishwashers, apparently. However, one proposal did come with a “6yr parts and labor warranty” from the contractor, for whatever that is worth.
Right now, the one I like the best has been the HTP Pioneer. It is about 1.5k more than the average combi proposal I have received, but from how it was explained to me, it is extremely low maintenance, completely eliminates short cycling, and is just as efficient as the wall mount setups.
My biggest concern is that these all seem oversized from what I have read but fail to understand. Each contractor has been able to explain why they aren’t oversized (they modulate down), but I don’t know what to think.
I used SlantFin, hopefully correctly, and came up with a 31k heat loss reading for the house. I also attached my consumption history for gas over the last two years.
I appreciate any help deciding that you could provide.
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