At 5:50 on Thursday morning, October 1, the house dipped below 63 degrees and the new furnace ran on its own for the first time this season. I only know because the ecobee app said so. It ran on low fire for about twenty minutes, and I slept through every bit of it, which is more or less the point of a two-stage furnace.
This is our third heating season in the Cape and the first with the new furnace. Here's what we did to get ready in the first days of October, and the numbers we'll be measuring against.
Two winters on one page
I keep every Consumers Energy bill in the house sheet by month. These are the heating-season gas bills from our first two winters:
- 2024 to 2025 (before insulation): November $98, December $162, January $214 (178 therms), February $201, March $139. Total $814, about 640 therms.
- 2025 to 2026 (after insulation, old furnace): November $84, December $139, January $171 (139 therms), February $158, March $112. Total $664, about 505 therms.
That's about 21 percent fewer therms. I'm careful about how much of that I hand to the insulation, because the two winters didn't have the same weather and the rates weren't the same either. What I can say is that the house felt different, the upstairs especially, and the ice on the main eaves was a lot smaller.
This winter changes a second variable. The old furnace was 80 percent efficient and the new one is 96, so on paper the same heat takes about a sixth less gas. "On paper" is doing real work there. Part of our gas goes to the water heater all year, about $38 to $42 a month in summer once you count the customer charge, and that part doesn't change. So I'm not going to predict a number. The baseline is 505 therms from November through March, and I'll compare against it in April.
The new furnace's first fall
The new Bryant takes a 4-inch media filter in its own cabinet, instead of the thin 1-inch filters the old furnace used. The installer said to check it at six months. I wrote the install date, August 19, on the edge of the filter in marker, added a February reminder to the sheet and put a spare on the basement shelf so I'm not hunting for one in a snowstorm.
In August the installer connected the second-stage wire to the ecobee. On Friday I went through its equipment settings, confirmed it sees two heat stages and set it to lean on low fire, so the second stage only comes on when the house falls behind or a run goes long. The schedule didn't change: 67 when we're home, 63 overnight and while we're away.
The two white vent pipes come out the side of the house close to where the snow from the driveway tends to pile up. That's a problem I'd rather solve in October than discover in January, so there's now a reflective stake next to them as a reminder not to aim the snowblower chute that way.
The $250 Consumers Energy rebate check arrived on Tuesday, September 29, which puts our net cost for the furnace at $6,850.
The rest of the October list
The carbon monoxide alarm outside the downstairs bedroom had been passing its test button for two years, so I'd never looked at the back. When I finally did on Friday, it said to replace it by a date that had passed in the spring. A new one cost $32 and went up that afternoon. With a gas furnace, a gas water heater and a freshly lined chimney in the basement, I'd like the alarms to be current, not just loud.
The back spigot gets shut off and drained in the next week or two, like last year, and the window film goes back on the two upstairs gable windows in November. And on Friday morning, standing at the coffee maker around sunrise, I saw a thin line of daylight under the back door. That's the threshold I skipped last November. It's getting replaced on Sunday.
The house sheet has a new row waiting, labeled 2026 to 2027, with five empty cells.
