Your home upgrade’s quoted price is fixed, but the loan behind it resets every month. A quarter-point rate bump adds about $9 to the median payment. That is a silent cost, and it never shows up on your initial quote.

Intercontinental Exchange (ICE) tracked the loan data in its October Mortgage Monitor. The median second-lien home equity line of credit (HELOC) sits at $44,000, at a median rate of 7.4% [1]. These lines track the prime rate and reprice monthly.

At the same time, heating and cooling makers sent out another round of October price hikes. Most landed in the 3% to 6% range. A few climbed much higher [2].

Neither industry hides its math. The blind spot is that the equipment quote and the loan terms rarely sit in the same folder.

The big picture:

Two clocks are running on a single home upgrade. The equipment price jumps when a maker issues a letter. The loan cost moves whenever the prime rate changes.

The Federal Reserve just moved that rate. On September 16 it raised its target range a quarter point, to 3.75% to 4% [3]. The vote was 12 to 0, and the statement cited high inflation. Bank of America lifted prime to 7.00% the next day, from 6.75% in December [4].

What strikes me here is how cleanly the two halves separate. The efficiency rating on a new heat pump is locked the day it goes in. The cost of the borrowed money is not locked at all.

Borrowers are already shifting toward floating money. Adjustable-rate mortgages (ARMs) took over 11% of rate locks, their largest share in nearly four years [1]. Active first-lien ARMs total 3.1 million, the most in five and a half years.

By the numbers

  • $44,000 — Median HELOC balance: the stock of second-lien lines, at a median 7.4% [1]. Fully drawn, that is about $3,256 a year in interest.
  • $9 a month — Cost per quarter point: ICE’s figure for the median HELOC payment [1]. Four hikes add about $36 a month, with no new money borrowed.
  • 3% to 6% — October equipment letters: the typical rise this month [2]. Aeris Metals lifted linesets 12.9% on average, and Robertshaw went as high as 15% on some products.
  • 6.6% — Remodeler input costs: the second-quarter rise in nonlabor inputs, up from 3.9% [5]. That is eleven straight quarters of gains.

What I’d watch:

The next Federal Open Market Committee (FOMC) meeting runs October 27 and 28 [6]. Whatever the Fed decides lands on the median HELOC within a month. That reset is a hard contract, not a bargain.

  • The ARM lock share: new locks sit above 11% [1]. The 2020 vintage matters most. About 74,000 seven-year ARMs from that year reset in 2027, with a median payment jump near $1,066 a month.
  • The letter dates: Panasonic’s 3.7% to 4.0% rise starts October 19, and Resideo’s lands October 31 [2]. A quote written across either date is a different price for the same box.
  • Fixed versus floating: the national average HELOC rate was 8.195% on October 5 [7]. A ten-year fixed home equity loan averaged 8.164%. Nearly the same price, but one contract can move and the other cannot.
  • Cash buyers: they are the only group with a fixed price on both the gear and the funding. I keep coming back to that gap. It is the whole case for paying cash when the reserve allows it.

The catch

My read is that this is a story about structure, not a crisis. Nine dollars is a tiny slice of a $44,000 balance. A household with some slack will absorb a few resets and never notice.

The scale moves with the line, though. At $100,000, a quarter point adds about $21 a month [1]. Four of them total roughly $83. Same contract, four times the exposure.

Two caveats matter. The 7.4% is the median of lines already open, many priced when margins were thinner. New lines advertise closer to 8.195% [7]. The newest borrowers pay more than the median book suggests.

The letters also price gear, not labor. The installed price is never just the list price. What the letters prove is direction and timing: the box got dearer this month, on dates a buyer can check.

One case in the desk’s file points at the deeper limit. A heat pump sized without a balance-point check produced a $920 electric bill in a single cold snap. That is one case, not a market rate. Still, the savings side is fixed at install, and everything else can move.

Home values are still climbing, which helps. The median existing-home price was $417,500 in September, up 1.3% for a 39th straight month [8]. Equity can absorb a larger loan. It cannot make the monthly payment, and that cash comes out of income.

At a glance

  • The Big Shift: Both prices inside a financed home upgrade rose in October. Makers sent out list increases of 3% to 6% [2]. The loan that pays for the equipment resets monthly off a prime rate the Fed raised in September [1][3].
  • Why It Matters: The only fixed numbers at signing are the equipment price and the efficiency rating. The cost of the money floats. A payback estimate that holds the rate steady overstates the return, and the error grows with each quarter-point rise.
  • What I’d Watch: The rate path and the price letters both carry dates, so the next moves are readable.
  • The October Fed meeting: a quarter point there adds about $9 a month to the median HELOC payment within one billing month.
  • The letter dates: a quote written across an effective date is a different number for the same equipment.
  • The ARM reset wave: about 74,000 seven-year ARMs from 2020 reset in 2027, pulling more cash from household budgets.
  • The Catch: The $9 figure is ICE’s median estimate, not an observed change, and it scales with the balance. New lines also price above the 7.4% median of the existing book.

Related reading

Sources

[1] Intercontinental Exchange, October 2026 Mortgage Monitor, published October 5, 2026 — https://mortgagetech.ice.com/resources/data-reports/october-2026-mortgage-monitor [2] The ACHR News, “HVAC Price Increase List: October 2026,” October 7, 2026 — https://www.achrnews.com/articles/166764-hvac-price-increase-list-october-2026 [3] Board of Governors of the Federal Reserve System, FOMC statement, September 16, 2026 — https://www.federalreserve.gov/newsevents/pressreleases/monetary20260916a.htm [4] Bank of America, prime rate information, effective September 17, 2026 — https://newsroom.bankofamerica.com/content/newsroom/home/prime-rate-information.html [5] National Association of Home Builders, Eye On Housing, “Q2 2026 Remodeling Market Update: Labor and Nonlabor Input Costs,” September 23, 2026 — https://eyeonhousing.org/2026/09/q2-2026-remodeling-market-update-labor-and-nonlabor-input-costs [6] Board of Governors of the Federal Reserve System, FOMC meeting calendar 2026 — https://www.federalreserve.gov/monetarypolicy/fomccalendars.htm [7] Fortune, “Home equity loan and HELOC rates: Oct. 5, 2026” — https://fortune.com/article/home-equity-rates-10-05-2026 [8] National Association of Realtors, “Existing-Home Sales Increased 1.5% in September,” October 13, 2026 — https://www.nar.realtor/newsroom/existing-home-sales-increased-1-5-in-september-according-to-nar-report