It's 10am on a Tuesday in September. Both your techs showed up. The truck is fueled. The phone hasn't rung since Friday.
You check the service board: one call scheduled at 2pm today, nothing tomorrow, a big empty box for the rest of the week. Payroll is Thursday.
We've all been there. This is the shoulder season — the part of HVAC slow season marketing that nobody talks about honestly: that three-week stretch where the summer workload is gone and the heating calls haven't started. The instinct — and I get it, because every marketing article tells you to do this — is to fire up Google Ads or post something on Facebook. Spend your way out of a slow stretch.
I'd like to make the case that that's the wrong move. The right move is already sitting in your contacts list. You've got 100, 200, maybe 400 past customers who already trust you, already paid you, and statistically, roughly 70% of them haven't had their system looked at this year. One text to that list can fill a week of jobs.
Here's exactly how to do it.
For the opposite problem — phones ringing off the hook but nobody can answer — see HVAC missed call text back.
What you'll get from this post:
- Why the HVAC shoulder season hits small shops harder than big ones (it's a cash flow thing)
- Why Google Ads is the wrong tool for your leanest month
- How to turn your existing customer list into a week of booked tune-ups
- 3 copy-paste SMS templates for fall and spring campaigns
- What realistic results look like — including one real campaign that generated 101 bookings and $38k in direct revenue
Why the Slow Season Stings (Especially for Small Shops)
There are two dead zones in the HVAC calendar. The first is September through October: summer cooling demand has dropped off, but it's not cold enough yet for people to think about their heat. The second is March through April, when heating season is winding down and nobody's sweating yet. In mild climates, you can add a stretch of November through February on top of that.
These windows hit a 1–5 truck operation differently than they hit a 20-truck regional company. Big shops have service agreement revenue flowing every month regardless of the weather. That recurring money smooths the dip. If you've got 500 maintenance plan customers paying $15–$20/month, slow season is an inconvenience. If you're running on reactive service calls and new installs, slow season is a cash flow crisis.
Payroll doesn't pause. Equipment loans don't pause. Your techs are standing around, you're burning their hours, and the phone isn't ringing. That's the real problem. It's not that revenue is below some annual target. It's that the monthly nut doesn't flex down with the call volume.
Why Google Ads Won't Save You in September
I've talked to enough HVAC owners to know this story: slow season hits, somebody suggests running Google Ads, you spend $400 over two weeks, you get four clicks and one call that turns into a tire-kicker, and you're now $400 deeper in the hole.
Here's why the math never works. HVAC Google Ads run $15–$40 per click on average in active season. New cold leads through paid channels cost $75–$400 each once you factor in click-to-conversion rates. Reactivating an existing customer costs a fraction of that. We're literally talking about the cost of a text message.
But the bigger problem with slow-season ads isn't just cost. It's intent. People aren't searching for HVAC service when nothing's broken and the weather's mild. There's less search volume to buy. So you're paying high CPC rates for a smaller pool of searchers, using money you don't have, on a channel with no guarantees.
Your existing customer list, by contrast, is free to contact. And the people on it already trust you.
For more on when paid search does make sense vs. organic, read HVAC Google Ads vs. organic on a $500 budget.
The Asset You Already Have: Your Customer List
Here's a stat I think every HVAC owner should tape to their desk: less than 30% of customers proactively schedule annual HVAC tune-ups. The other 70% don't forget because they don't care. They forget because life is busy and nobody reminds them. (ZyraTalk HVAC SMS Guide)
That other 70% is your slow-season revenue. They just need you to ask.
Most HVAC owners have 100–500 past customers sitting in their CRM, their invoicing software, their QuickBooks, or their Google Contacts. Sitting there. This is the highest-ROI marketing asset you own, and it goes untouched every September.
Here's why texting those customers specifically is the right move, not emailing them:
- SMS open rate: 98%. Email open rate: around 20%. There's no comparison. (ZyraTalk)
- SMS response rate: 45%. Email response rate: around 8%. (ZyraTalk)
- 90% of text messages are read within 3 minutes of being received. (SMS Works)
When you send an email, it competes with 87 other unread messages and maybe gets seen tomorrow. When you send a text, it lands on a phone screen and gets read almost immediately. For a time-sensitive offer ("we have 8 tune-up slots open this week"), text is the only channel that actually captures that urgency.
How to Run an HVAC SMS Broadcast Campaign
Four steps. None of them require a marketing background.
Step 1 — Segment Your List First
Don't blast your entire contact database at once. Start with your warmest contacts: customers who've booked with you in the last 12–18 months. These people remember you. Their relationship with your business is recent. They're far more likely to respond to a text offer than someone whose system you worked on three years ago who may not even remember your company name.
Once you've worked through your most recent customers, you can expand to the 18–36 month window. Past that, the response rates drop noticeably, and you'll want to adjust your message (a softer reconnect rather than a direct offer).
One thing to flag before you send: check for customers who already have an active maintenance agreement with you. Don't send them a tune-up offer. They're already covered, and it reads as disorganized. Take them off the broadcast list.
Step 2 — Pick Your Offer
You've got three options that consistently work for HVAC slow-season campaigns.
The tune-up special. Give it a specific price. "Fall furnace tune-up, $79" is an offer. "Discounted HVAC service" is not. The more specific the number, the more seriously people take it. Combine this with a real scarcity signal ("we have 10 slots open this week"), because for a small shop, that's actually true.
The early-book discount. This one works well in spring: "Book your AC check now before the rush hits and save $40." You're filling your calendar during the slow stretch and giving customers a reason to act before they naturally would. It creates demand where there wouldn't otherwise be any.
The referral ask. This one requires no discount at all. You're just asking your happiest recent customers to pass your name along. It doesn't fill next week's schedule directly, but it's the highest-margin lead generation you can do. A simple, personal text from you to your top 20–30 most recent customers will produce referrals if your work has been solid.
Step 3 — Timing the Send
The best days: Tuesday, Wednesday, Thursday. Best window: 10am–1pm. This isn't arbitrary. It's what the data consistently shows for service-business SMS campaigns. Monday mornings people are in reactive mode and annoyed by anything that feels like marketing. Friday afternoons they've mentally checked out. Weekends are personal time and your response rates will be lower.
For fall campaigns, early September is the sweet spot. You're just ahead of the weather transition, people are getting back into routine after summer, and you have real capacity to fill. For spring, send in early March, before the AC rush puts you into reactive mode.
Don't send after 7pm. A text at 9pm from your HVAC company reads as intrusive even if the offer is good.
Step 4 — Have a Reply Plan Before You Send
This is the step most people skip and then regret. If you text 150 customers and 25 respond "Yes, interested" within the first few hours, you need to be ready to respond fast. Slow replies kill the conversion rate. Someone says yes to a tune-up, then doesn't hear back from you for 6 hours, and they've mentally moved on.
Have your response ready before you hit send: a calendar link, a simple "What days work for you this week?" or a list of two or three available times. Aim to reply within an hour of any incoming response. For a 150-person broadcast, you might see 20–35 replies. That's a manageable afternoon, and it's a very good problem to have.
The 3 Templates — Copy and Paste These
These are ready to use. Swap in your own name, business name, pricing, and slot count. Each one is under 160 characters in its core message, which keeps it as a single SMS.
Template 1: Fall Furnace Campaign Use in September–October, before heating demand spikes.
Hi [First Name], it's [Your Name] from [Company]. We have 10 fall tune-up spots open this week — $79 for a furnace check before winter. Want one? Reply YES and I'll send you times. Reply STOP to opt out.
Template 2: Spring AC Campaign Use in March–April, before cooling demand picks up.
Hey [First Name] — [Your Name] at [Company]. Before the AC rush hits, we're booking spring tune-ups at $69. Only a few slots left this week. Want to grab one? Reply YES for available times. Reply STOP to opt out.
Template 3: Referral Ask Use year-round with your most recent 20–30 customers. No discount needed.
Hi [First Name], hope the system's been running well. If you know anyone who needs HVAC work, we'd love the referral — we'll take great care of them. Thanks for being a customer. — [Your Name], [Company]
A note on compliance: if you're sending to a list of 50 or more people, always include a clear opt-out instruction ("Reply STOP to opt out"). You have an established business relationship with past customers, so you're generally on solid legal footing. The opt-out line is industry-standard practice and keeps you covered. This isn't legal advice; if you're building out a larger list, it's worth a quick review of TCPA guidelines.
What to Expect: Real Results and How to Measure Them
Here's the ceiling. One HVAC company ran a reactivation campaign to a dormant customer list and generated 101 booked appointments, $38,000 in direct service revenue, and another $29,000 in upsells — roughly $67,000 total — with bookings coming in within 48 hours of the first text send. (Relentless Digital)
That's a genuine result and I'm not going to pretend it's typical. It came from a well-segmented list, a strong offer, and a team ready to handle the response volume. But it's a useful ceiling to understand what's possible from a list you already own.
For a smaller operation (say, 150–250 contacts with a tight offer), here's what a realistic first campaign looks like:
- 20–35 responses (roughly 15–20% response rate)
- 12–20 booked appointments (60–70% of responses convert)
- $900–$3,000 in direct tune-up revenue at $69–$150 per job
- Several leads that convert to larger repairs or equipment replacement (tune-ups have a way of turning into new installs when you're actually in front of the system)
What to track:
- Response rate: the percentage of people you texted who replied. Aim for 15–25%.
- Booking rate: the percentage of responses that became a booked appointment. Aim for 60–80%.
- Revenue per send: total campaign revenue divided by number of texts sent. Even $5–$10 per text sent is excellent ROI by any marketing standard.
What it's not: magic. A list that hasn't been contacted in four years, with a vague offer, sent on a Saturday night, won't look like any of these numbers. The steps above exist because each one meaningfully moves the result.
How ConnectFirst Makes This a 10-Minute Job
Everything described above can be done manually. Export your customer list to a spreadsheet, filter by last service date, import into a generic texting tool, personalize each message, track replies in a separate tab, try to keep up with who responded to what. It works. It takes 2–3 hours, it's error-prone, and it falls apart when you're trying to handle replies while also running a service call.
ConnectFirst is built for this workflow. You segment your list by last service date, write one broadcast template with personalization tokens, hit send, and manage every reply in a single inbox with the customer's context in the thread. The whole thing takes about 10 minutes, and you're not juggling four different apps to do it.
If you want to try it before committing, reach out through our contact form and we'll set up a quick demo.
Ready to Run Your First Broadcast?
ConnectFirst lets you filter your customer list, send a personalized broadcast, and manage every reply in one place. No spreadsheets, no duct tape, no missed responses while you're on a job. Get in touch →
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Frequently Asked Questions
When is the HVAC slow season?
The two slowest windows are September–October (end of cooling season, before heating demand picks up) and March–April (end of heating season, before AC season). In mild climates, November through February can also be soft. For most small shops, September is the single worst month of the year. The phones just stop.
Is it legal to text my past HVAC customers?
In most cases, yes. If a customer gave you their phone number when they hired you, you have an established business relationship that covers outreach. Always include an opt-out line ("Reply STOP to opt out") in any broadcast. This isn't legal advice. If you're scaling up a large list, take a look at TCPA guidelines or check with an attorney.
How often should I text my customer list?
Two to three times per year is a reasonable cadence for a reactivation program. A fall furnace push, a spring AC push, and optionally a year-end equipment-replacement message covers the calendar without wearing out your welcome. More than that and you'll see opt-outs climb.
What if I don't have everyone's cell number?
Start with what you have. Even 40–50 customers with cell numbers can produce a week of booked jobs with the right offer. Going forward, make getting a cell number a standard part of every service call intake. Within a season or two, your list will be large enough to produce consistent results every time you send.
What should the offer be?
Specific beats vague every time. "$79 fall furnace tune-up — 10 slots left this week" outperforms "ask us about our seasonal specials." Pick a real price, pick a real number of available slots, and put both in the text.
Key Takeaways
- The HVAC shoulder season (Sept–Oct and March–April) is a cash flow problem, not a revenue problem, and it hits 1–5 truck shops harder than anyone.
- Running Google Ads in your leanest month is bad math: high CPCs, low search intent, thin bank account.
- Less than 30% of your past customers will proactively book a tune-up. The other 70% just need you to ask.
- SMS beats every other channel for this: 98% open rate, 45% response rate, most messages read within 3 minutes.
- The right offer (specific price, real scarcity), the right timing (Tues–Thurs, 10am–1pm), and a short personal text = a full week of booked jobs from a list you already own.
- A real HVAC reactivation campaign produced 101 bookings, $38k in direct revenue, and $29k in upsells from a dormant list.
- You can do this manually in an afternoon, or streamline it with ConnectFirst.
ConnectFirst helps HVAC shops text missed calls, follow up on quotes, and reactivate customers — without adding work for the tech in the field. Book a demo →