Massachusetts Heating Season: The Boiler Permit Clock
By the permits.llc team · Last reviewed October 1, 2026 · Optimal window: Weeks 1–2 after a furnace or boiler record files; Weeks 1–4 after a heat-pump record files
TL;DR
- Massachusetts landlords must supply heat from September 16 under 105 CMR 410.201. The permit wave follows that calendar.
- Furnace and boiler records ran 452 a month October to January against 241 a month May to August.
- Heat-pump records run the opposite way, peaking in June 2026, when they outnumbered boiler records for the first time.
- Boilers file as gas and plumbing permits; heat pumps as electrical and sheet metal. Filter the trade stream.
Massachusetts furnace and boiler replacements run on a winter clock and heat-pump installs run on a summer clock, and the two barely overlap. From October 2025 through January 2026 our Massachusetts permit file carried 452 furnace or boiler records a month, almost double the 241 a month it carried from May through August 2025. Heat-pump records did the reverse: their low was October 2025 at 159, their high was June 2026 at 284, and June 2026 was the first month in the series where heat pumps outnumbered boilers.
The legal calendar behind the winter clock is 105 CMR 410.201, the temperature section of the State Sanitary Code: 68°F by day, 64°F overnight, every day other than June 15 through September 15. Heat became mandatory again on September 16, five days ago, and the record shows the replacement wave starting in September and doubling by October.
A permit is a signal about the homeowner, not the contractor. A boiler record filed in November is a household that just spent several thousand dollars in a hurry, with a licensed contractor already chosen. A heat-pump record filed in June is a household that planned, applied for a rebate, and is still mid-project. Different leads. This piece is about telling them apart in the feed.
What does the Massachusetts heating season do to the permit record?
The heating season turns a slow, planned equipment market into a fast, forced one, and the permit record shows the turn within weeks of September 16. In our file, records whose work description names a furnace or boiler ran 219 in August 2025, 333 in September, 493 in October and 496 in November. That is a 126% increase in two months, in a file whose total monthly volume rose only 20% over the same stretch.
The obligation is specific. 105 CMR 410.201 says the owner shall provide heat in every habitable room and every room containing a toilet, shower or bathtub to at least 68°F between 7:00 A.M. and 11:00 P.M. and at least 64°F between 11:01 P.M. and 6:59 A.M., every day other than June 15 through September 15, both inclusive. The temperature may not exceed 78°F during the heating season. The only exceptions are a written lease that makes the occupant responsible for fuel, and a variance from the local board of health under 105 CMR 410.840.
Two things about that rule matter for lead work. It is an obligation the owner owes the occupant, enforced by the local board of health, so in practice it bites on rental housing: the multi-family stock in Somerville, Melrose and Belmont is where September 16 carries legal weight. And our data cannot separate rental from owner-occupied records, so the table below is the whole market. The sanitary code is the calendar the wave follows, not a proven cause.
A replacement also needs a permit, and the permit belongs to the trade. Boston files a like-for-like water heater or boiler replacement, "when no other work needs to be done, such as opening up walls," as a plumbing permit that only a contractor with a valid Massachusetts trade licence may pull. Gas-fired equipment runs on a gas permit under 248 CMR. Oil-fired equipment goes to the fire department, which gets its own section below.
The 19-month heating permit table
Every row is a count of Massachusetts records in our file, January 2025 through July 2026, whose work description names a furnace or boiler, or a heat pump, mini-split or ductless unit. Duplicates are excluded. The month is the application date where the town publishes one, otherwise the decision date.
| Month | Furnace / boiler | Heat pump | Boilers per heat pump |
|---|---|---|---|
| Jan 2025 | 569 | 189 | 3.0 |
| Feb 2025 | 416 | 139 | 3.0 |
| Mar 2025 | 358 | 193 | 1.9 |
| Apr 2025 | 350 | 201 | 1.7 |
| May 2025 | 296 | 238 | 1.2 |
| Jun 2025 | 221 | 208 | 1.1 |
| Jul 2025 | 227 | 192 | 1.2 |
| Aug 2025 | 219 | 191 | 1.1 |
| Sep 2025 | 333 | 164 | 2.0 |
| Oct 2025 | 493 | 159 | 3.1 |
| Nov 2025 | 496 | 183 | 2.7 |
| Dec 2025 | 422 | 184 | 2.3 |
| Jan 2026 | 396 | 165 | 2.4 |
| Feb 2026 | 362 | 127 | 2.9 |
| Mar 2026 | 361 | 164 | 2.2 |
| Apr 2026 | 295 | 211 | 1.4 |
| May 2026 | 264 | 178 | 1.5 |
| Jun 2026 | 218 | 284 | 0.8 |
| Jul 2026 | 266 | 271 | 1.0 |
Totals: 6,562 furnace or boiler records and 3,641 heat-pump records over 19 months. A record that names both, a boiler coming out and a heat pump going in, counts in both columns; there were 282 of those. Three caveats, stated once. This is one heating cycle, not a decade of them, so treat the shape as strong and the exact ratios as provisional. It counts records whose description names the equipment, so towns with terse portal descriptions are undercounted. And August and September 2026 are left out on purpose: the mix of towns reporting heating descriptions changed in August, so those months do not compare.
The shape survives the caveats. In every month from October through February, boilers outnumbered heat pumps at least two to one. In June and July 2026 they did not.
Why do boilers and heat pumps run on opposite clocks?
Because a boiler replacement is usually a failure and a heat-pump install is usually a decision, and failures cluster in the months the equipment is working hardest.
A 20-year-old boiler in Billerica does not fail in June. It fails on the first hard week of November, in a house that is legally required to be at 64°F at 3 A.M., with a plumber who can be there Thursday. The homeowner takes the like-for-like unit the plumber has on the truck. Nobody in that kitchen is scheduling a Home Energy Assessment. The Mass Save whole-home heat-pump rebate still carries a weatherization prerequisite in 2026, which is a sensible rule and a slow one; it is not built for a house with no heat.
The heat-pump clock is the mirror image. The homeowner who files in May or June has usually been through the assessment, chosen a network installer, and picked a month when the old system's failure is not the driver. That is why heat-pump records climb through spring and peak in early summer, and why the fuel-switch signal we described earlier this year is a spring and summer signal.
So the fall heating wave is the season electrification loses, and it is also the season with the most heating permits per month, and the two facts belong together. Every furnace or boiler record filed between October and January is a house that will heat with the fuel it just committed to for another fifteen years or more. If you sell the conversion, the window to reach that house was last spring, and the fall record is the list of households you did not reach. If you sell the adjacent work, it is the best list you will get all year.
Which permit stream does a heating replacement file in?
A furnace or boiler replacement files in the gas and plumbing streams, and a heat pump files in the electrical and sheet metal streams; almost nothing files as a building permit. Here is the split for the same 19 months.
| Permit stream | Furnace / boiler (6,562) | Heat pump (3,641) |
|---|---|---|
| Gas | 3,507 (53%) | 14 (under 1%) |
| Plumbing | 1,370 (21%) | 76 (2%) |
| Electrical | 890 (14%) | 1,557 (43%) |
| Sheet metal | 503 (8%) | 1,332 (37%) |
| Building | 188 (3%) | 404 (11%) |
| Mechanical | 95 (1%) | 257 (7%) |
The operator consequence is blunt. A feed filtered to building permits sees 3% of the boiler market and 11% of the heat-pump market. Filter by permit type gas plus plumbing with a description keyword of furnace or boiler for the winter clock, and by permit type electrical plus sheet metal with a keyword of heat pump, mini-split or ductless for the summer clock. Run both, separately: the two lists want different messages and different timing.
The stream also tells you who is on the record. A contractor name appears on 52% of furnace and boiler records and 61% of heat-pump records, and where it appears it is a licensed plumber, gas fitter, electrician or sheet metal contractor. For an adjacent trade that name is the referral partner, not the competitor. The reactive-versus-planned scoring method applies cleanly here: the gas-stream boiler record in November is reactive, the electrical-stream heat-pump record in May is planned.
The oil blind spot: what the building-department feed does not show
Oil burner replacements are permitted by the fire department, not the building department, so a building-portal feed undercounts them in a state where one household in five heats with oil. The Department of Energy Resources' home heating profile, citing the 2024 American Community Survey, puts Massachusetts at 1,472,791 households on utility gas (52%), 572,376 on fuel oil or kerosene (20.2%), 578,927 on electricity (20.5%) and 124,926 on bottled or tank gas (4.4%).
The fire-department route is statutory. 527 CMR 1.00, the Massachusetts Comprehensive Fire Safety Code, and M.G.L. c. 148 put the installation and alteration of oil-burning equipment under the head of the local fire department, who issues the permit on Department of Fire Services form FP-056, "Form 1." Fire departments from Mashpee to Topsfield to Plymouth post the process on their own pages. None of them publishes those permits into the building-department portals that feed permit data, ours included.
Read the town figures with that in mind. Over the 19 months, the towns producing the most furnace and boiler records were Falmouth (819), Somerville (593), Billerica (568), Taunton (395), Holliston (325), Belmont (323), Melrose (322) and Bellingham (307). For heat pumps: Somerville (574), Falmouth (382), Melrose (273), Holliston (244), Billerica (226), Belmont (195), Holden (172) and Concord (161). Somerville files almost exactly one heat-pump record for every boiler record. Falmouth files one for every 2.1, Billerica one for every 2.5. Those ratios describe the gas and electric portions of each town's market. The oil portion is a further, unmeasured layer on top, and it is largest exactly where the ratios are already boiler-heavy.
In oil towns, then, the boiler count you see is a floor. The oil replacement still leaves tracks: the electrical permit for the burner circuit, the plumbing permit if the indirect water heater goes at the same time, and later the tank removal that follows a conversion.
How to work the October to January wave
The fall boiler record is a completed sale for the HVAC trade and an open one for everyone around it, so work it as an adjacent-trade list with a two-week clock.
Chimney and venting. A new gas boiler or furnace vented into an old masonry chimney is the most common reason a chimney liner permit files a month later. If the boiler record names a high-efficiency or condensing unit, the old flue has just been orphaned by whatever water heater still vents into it. Reach the owner inside two weeks.
Electrical service and generators. Every heating replacement touches the panel, and the November boiler owner has just been reminded what a cold house feels like. A household that has just spent on heat will listen to a pitch about keeping it running through an outage.
Insurance and property management. For a multi-family owner, the record proves the building can meet the 68°F and 64°F thresholds this season. That is a renewal conversation for an insurance broker and a compliance file for a property manager.
The message. Name the date and the rule, not the fear.
Subject: Your new boiler at [street], and the flue it left behind
Hi [Owner first name],
I saw the gas permit filed for the boiler replacement at [street] on [date]. When a high-efficiency unit goes in, the old chimney is usually left venting only the water heater, which is the setup that fails a liner inspection. We have crew days open in the first two weeks of [month] and can inspect and, if needed, line the flue before the cold sets in.
[Your Name], [Company], [phone]
The same note, keyed to the electrical permit and the heat-pump keyword, works in May with a different second sentence: the fall version protects a purchase already made, the spring version joins a project still open. Do not send the spring note in November. The owner has already decided.
And for the HVAC contractor who sells heat pumps: the fall record is your research list, not your prospect list. The households in it replaced under duress; their neighbours with the same-age equipment are next winter's boiler records, unless someone reaches them in April.
How permits.llc fits in
permits.llc aggregates more than 410,000 Massachusetts permit records across 13 counties with data, refreshed daily from official municipal portals, and it carries gas, plumbing, electrical and sheet metal records in the same feed as building permits. That is what makes the two-clock cut possible: the boiler wave lives in the gas and plumbing streams, the heat-pump wave lives in the electrical and sheet metal streams, and a building-permit-only feed sees neither.
Start with the free dataset at the permit download page and run the 19-month table for your own county, then set up daily alerts for gas and plumbing permits in your towns so that this October's boiler records, which on last year's shape will arrive at twice the summer rate, reach you in the two weeks that matter.
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