It is 9:40 on a Saturday night in the middle of July. Your phone rings, rolls to voicemail, and the homeowner hangs up without leaving a message. By Monday somebody else has already been out to look at their condenser. You never even knew the call happened.
That math is what pushes most contractors to start looking at AI answering services. Not curiosity about AI. A number. If you run three trucks and you miss five or six calls a week, you have a rough idea what that costs you, and it is almost always bigger than what any answering service charges.
Rosie comes up early in that search, and for good reason. What follows is what Rosie actually is, where it is a genuinely good buy, what makes HVAC calls their own animal, and where Thermoi is built differently. We make Thermoi, so weigh this accordingly. We also say plainly below where Rosie is the better purchase for your shop, because that is true for a lot of shops.
What Rosie AI actually is
Their homepage headline reads "The easiest AI answering service for small business," and their own structured data describes the service type as AI Virtual Receptionist Service. It picks up inbound calls around the clock, answers caller questions, takes messages, books appointments, and texts you the details of every call. Their site says it trains itself on your Google profile and your website.
Pricing is published, which is more than a lot of vendors in this category do. Three monthly plans: Professional at $49 for 250 minutes, Scale at $149 for 1,000 minutes, and Growth at $299 for 2,000 minutes. Website chat is free on every plan. Website texting is a $50 monthly add-on that includes 25 conversations, then $1 per conversation after that. The trial is published as a 7-day free trial, cancel anytime. Their Terms of Service also describe a fourth Custom Plan whose pricing you have to ask for.
Read the tiers closely, because the feature most contractors assume they are buying does not sit on the cheapest one. Calendar appointment booking, warm transfers, and live call transfers all start at the $149 Scale plan. The $49 Professional plan gets custom message taking with two scenarios, spam detection, and the website chat widget. Waterfall transfers, where Rosie tries multiple numbers until somebody picks up, live on the $299 Growth plan, along with uploading your own training documents and white glove onboarding.
Minutes are billed in 60-second increments and rounded up, per their Terms, measured from the moment the caller connects to the moment the call disconnects. No per-minute overage rate appears anywhere on their pricing page. What their Terms say instead is that going over your allotment automatically upgrades you to a higher plan, and you stay on that higher plan going forward unless you downgrade. You will find third-party review sites quoting a flat per-minute overage charge. That figure is not on Rosie's own site and it contradicts their own contract language, so do not budget around it.
On scheduling, their help center documents exactly four calendar connections: Calendly, Google Calendar, Appointlet, and Acuity Scheduling. That same article lists appointment rescheduling and cancellation under Coming Soon, so by their own documentation a caller cannot yet move or cancel a booking through Rosie. Beyond calendars there is Zapier, with triggers for New Call, Updated Call, and New Booking. No field service platform is named on their HVAC, home services, or plumbing pages, and no help article names a CRM. Whether you could rig something together through Zapier is a separate question. They do not document it.
The last thing worth knowing is how broadly they sell. Their sitemap carries 27 industry pages: HVAC, plumbing, electricians and roofing, but also law firms, dentists, salons, funeral homes, veterinary clinics and restaurants. Rosie says 2,000 plus small businesses use it. There is a real HVAC landing page with real HVAC language on it, quoting callers saying their air conditioner will not turn on, so anyone telling you Rosie has nothing for HVAC is wrong. It is a horizontal small business answering service that has an HVAC page, not a product built around the trade.
Where Rosie is genuinely the right call
There is a version of a contractor for whom Rosie is the obvious answer, and we would rather say that than pretend otherwise.
If what you actually need is for the phone to stop rolling to voicemail, and a text to land on your phone with the name, the number, and what they want, Rosie does exactly that starting at $49 a month and you can sign yourself up tonight without talking to a salesperson. That is a real deal. For a one truck shop where you are the dispatcher, the tech, and the guy doing invoices at 10pm, a clean message with a transcript is most of the value you were looking for anyway.
It is also the better buy if HVAC is not your only business. Plenty of guys run heating and air plus a small property maintenance outfit, or have a second company on the side. One vendor covering both, at a price you can see before you talk to anyone, is worth something.
Same story if you already book through Google Calendar or Calendly and you are happy with it. Rosie's booking is pointed straight at that setup. Same if what you want is a phone app with push notifications on every lead, Spanish on every call, or a chat widget on the site thrown in for free.
Where we would push back is not on Rosie. It is on the assumption that answering a small business phone and making an HVAC dispatch decision are the same job.
Why HVAC calls are their own problem
Take a normal week in the middle of a heat wave. The first 95 degree stretch of the season hits and your volume does not climb 20 percent, it doubles, and it doubles inside about four days. Three people call at the same time on Tuesday at 4:15. Two of them have a system that will not start and one wants a quote on a maintenance plan. The order you call those three back in is the whole ballgame.
That is triage, and it is a different job from taking a message. A message taker gets you all three names. Triage tells you which one is a same day dispatch, which one is a Thursday morning slot, and which one can wait until you have capacity. Getting that wrong in July costs you twice: the emergency call you could have billed, and the customer who phoned someone else while your truck was driving to a filter change.
Then there is the after-hours load. Nobody's furnace quits at 10am on a Wednesday. It quits at 5:30 on a Friday in February and at 11pm on a Sunday in August. If you run an on-call rotation, the answering layer has to know who is on tonight, has to actually reach that person, and has to keep trying when the first number does not pick up. If it cannot do that, you are still the one waking up to a notification and forwarding it yourself.
The calls are also long. A real intake is not thirty seconds. You need the address, whether they own or rent, what the system is doing, roughly how old it is, gas or electric, whether it is fully down or just running poorly, whether there is an infant or an elderly parent in the house, and then you still have to put them on the schedule. Price any minute based plan against your own average handle time before you sign anything. Take your monthly call count, multiply by what your calls actually run, and see which tier that lands in. Use your numbers, not the example on the pricing page.
Last piece, and it is the one that decides most of this: what you are holding when the call ends. A message in an inbox is a task you still have to do. An appointment on the board is work that is already sold. The gap between those two is where the after-hours money leaks out of a small shop.
Where Thermoi fits
We built Thermoi for one trade. Every other decision follows from that.
Thermoi answers your inbound calls 24/7, qualifies the caller, books the appointment while they are still on the phone, and routes a genuine emergency to whoever is on call that night. Every call comes back as a full transcript. The idea is that you wake up to a schedule instead of a list of callbacks.
Pricing works differently from Rosie's, and you should know that going in. Monthly plans start at $299. We do not publish per-tier prices, because the plan gets sized on a 15-minute demo around your real call volume. Some contractors hate that, and it is a fair thing to hate. What we do publish is the way in: a $50 two-week pilot that runs on your actual phone line, not a demo number, so you hear what your own customers hear before you commit to anything. No setup fees, no contracts, month to month, and a 90-day money-back guarantee. Most shops are live in under 48 hours.
Now the part we are not going to dress up. Thermoi is early and pre-revenue. We have no customer count to wave at you, no case study numbers, and no list of shops in your market you can call for a reference. If a long roster of other businesses already using it is what makes you comfortable signing, we do not have that yet, and you should weigh it honestly. What we can offer instead is $50 to hear it on your own line for two weeks and 90 days to get your money back if it does not do what we said. That is the trade at this stage, and we would rather put it in writing than let you discover it later.
The other limitation is narrower and simpler. We only do HVAC. If you want one vendor answering for your heating and air company and your landscaping crew, that is not us. More at https://www.thermoi.com.
How to actually decide
Put the feature lists down and answer four questions about your own shop.
What happens right now at 11pm? If the honest answer is voicemail, nearly anything beats it, and the cheapest option that gets a live pickup is already a real improvement. If the answer is that your wife or your service manager is fielding calls on a personal cell, then coverage is not your problem. Whether the AI books as well as they do is your problem.
Do you need messages, or do you need appointments on the board? Be honest with yourself. Message taking is cheaper and it is plenty for a lot of shops. If you are fine calling people back at 7am and you close most of them, buy the cheap thing and stop reading. If your close rate falls off a cliff when you call back six hours later, you are shopping for booking, and once you are shopping for booking the sticker price differences stop mattering very much.
How much of your revenue rides on emergency work? A shop living on maintenance agreements and planned changeouts has a completely different phone than a shop that runs on no heat calls all winter. The more of your money arrives through emergencies, the more the triage and on-call routing layer is the actual thing you are buying.
And what is a missed job worth? Run it. If your average ticket is $450 and you are missing five calls a week, you are not choosing between $49 and $299. You are choosing between recovering part of roughly $9,000 a month or not.
Then test it. Rosie publishes a 7-day free trial you can cancel anytime. Thermoi runs a $50 two-week pilot on your live line. Both are cheap enough that thinking about it for another month is the expensive option. Call your own number at 10pm and listen to what a customer hears. That will tell you more than any comparison post, this one included.
Keep reading
The side by side version of this lives on the Thermoi vs Rosie AI comparison. For what an AI answering service actually does on each call, start with the HVAC answering service overview, and the pricing page has the $50 pilot and the ROI calculator on it.
Call patterns differ by market. There are breakdowns for Phoenix, Houston, Dallas, Miami, and Atlanta.
Questions people ask before they switch
Is Rosie AI a good fit for HVAC contractors?
It can be. Rosie has a dedicated HVAC landing page and HVAC blog content, and plenty of small shops are happy with a general answering service. What it is not is a product built around the trade. Rosie sells across 27 industries, and their own documentation names no field service software and no HVAC dispatch logic. If a live pickup and a good message is the job, that fits. If emergency triage and on-call routing is the job, look harder before you sign.
How does Thermoi pricing compare to Rosie?
Rosie publishes three monthly plans: $49 for 250 minutes, $149 for 1,000 minutes, and $299 for 2,000 minutes, with a 7-day free trial you can cancel anytime. Thermoi starts at $299 a month and does not publish per-tier pricing, because the plan is sized on a 15-minute demo around your call volume. No setup fee, no contract, month to month, a 90-day money-back guarantee, and a $50 two-week pilot on your real line to start. If lowest sticker price is the deciding factor, Rosie's $49 tier wins outright. Just check which features sit on which tier before you assume what $49 covers.
Does Rosie integrate with ServiceTitan, Housecall Pro, or Jobber?
Rosie does not document an integration with any field service management platform. Their HVAC, home services, and plumbing pages name none of them, and neither does their help center. What they do document is Zapier, with New Call, Updated Call, and New Booking triggers, plus four calendar connections: Calendly, Google Calendar, Appointlet, and Acuity Scheduling. Whether you can wire something together through Zapier yourself is a question for them. For Thermoi, bring your current stack to the demo and ask how it would fit.
What happens if I go over my minutes on Rosie?
Their pricing page publishes no per-minute overage rate. Their Terms of Service say that exceeding your monthly minutes automatically upgrades you to a higher plan, and you remain on that higher plan going forward unless you downgrade. Minutes are billed in 60-second increments, rounded up, measured from connect to disconnect. Several third-party review sites quote a flat per-minute overage charge instead. That number does not appear on Rosie's own site and it conflicts with their contract, so plan around the automatic upgrade.
Can an AI answering service really handle a 2am emergency call?
Answering it is the easy part. What matters is what the system does next: whether it can tell a house with no heat in February apart from a routine filter question, and whether it can actually reach the tech who is on call tonight. Thermoi routes genuine emergencies to the on-call tech and books the routine work into the schedule during the same call. Rosie's site describes live and warm transfers starting on the $149 plan and waterfall transfers, where it tries multiple numbers until someone answers, on the $299 plan. Either way, test it on your own line in the middle of the night before you trust it with a February weekend.