How to Set Your HVAC Service Call / Diagnostic Fee (2026)

The diagnostic fee is the first price most customers hear from your shop, and it's the one many owners set by guessing. They look at what the shop down the road charges, knock a little off, and hope the repair makes up the difference. Sometimes it does. On calls where the customer says "no thanks" after the diagnosis, it usually doesn't. Then you've paid a tech, a truck, and a share of your overhead to hand out free advice.

This guide shows you how to build a service call fee from your own costs, how to decide whether to credit it toward the repair, how to price after-hours calls, and what to say on the phone so the fee doesn't scare off good customers. It's written for shop owners and for techs about to open a shop.

All worked examples below use made-up round numbers to show the math. They are not industry averages. Swap in your own.

A note on "typical" fees: you'll find plenty of "the average HVAC service call costs $X" claims online, and most of them don't say where the number came from. Your local market, drive distances, and costs matter more than a national figure anyway. So this guide doesn't give you a range to copy. It gives you the math to compute your own.

What the diagnostic fee actually covers

A service call fee (also called a trip charge, dispatch fee, or diagnostic fee) pays for getting a qualified tech to the door and finding out what's wrong. It is not a "fee for showing up." It covers real costs that happen whether or not the customer buys a repair:

The tech's time on the call: drive there, time on site to test and diagnose, and the time to explain the options to the customer.
The truck: fuel, wear, insurance, and payments, spread per mile or per call.
Your overhead share: dispatch, office staff, software, rent, marketing that made the phone ring, and the owner's salary.
A profit margin. A diagnosis is skilled work. It should earn money on its own, not just break even.

Be clear with yourself (and your team) about what the fee does and doesn't include. A common setup is: the fee covers the trip and the diagnosis, and any repair is priced separately and approved by the customer before work starts. Write that down so every CSR and tech says the same thing.

Step by step: compute your fee from your real costs

Here's the full chain, using example numbers only.

Step 1: Time per diagnostic call. Pull your last few months of tickets and find your average time for a no-repair diagnostic call, door to door. Include drive time and time spent explaining options. Say it's 0.5 hours of driving and 0.75 hours on site: 1.25 hours total.

Step 2: Loaded labor cost per hour. A tech earns $30/hour. Payroll taxes, workers' comp, insurance, PTO, and other benefits add, say, 45%. Loaded cost = $30 x 1.45 = $43.50 per paid hour. (If you don't know your own burden, add up a year of payroll taxes, comp premiums, benefits, and PTO paid, and divide by a year of gross wages.)

Labor for the call = $43.50 x 1.25 = $54.38.

Step 3: Truck cost per call. Take a year of vehicle costs (payments or depreciation, fuel, insurance, repairs, tires) and divide by miles driven. Say that's $0.70 per mile and your average call is a 20-mile round trip. Truck cost = $0.70 x 20 = $14.00.

Step 4: Overhead per call. Take the overhead that belongs to your service side for the year (office, dispatch, software, rent, marketing, owner salary, and so on) and divide by the number of service calls you run in a year. Say that's $180,000 of service overhead over 3,000 calls. Overhead per call = $180,000 / 3,000 = $60.00.

If you'd rather work in overhead per billable hour, our free HVAC break-even hourly rate calculator gets you there. Just be consistent: use one method, not both.

Step 5: Break-even fee. $54.38 + $14.00 + $60.00 = $128.38. This is what one diagnostic call costs you. Charge less than this and every call that ends without a repair loses money.

Step 6: Add your profit as a margin, not a markup. Say you want a 20% margin on the fee. Fee = $128.38 / (1 - 0.20) = $160.48. Round up, to $165 in this example.

A 20% markup would give $154.06, and your real margin would be only about 16.7%. If markup and margin still trip you up, our HVAC markup vs margin calculator converts between them, and the flat-rate vs time and materials guide explains the difference with more examples.

Should you waive or credit the fee if they buy the repair?

Many shops credit the diagnostic fee toward the repair ("the $165 goes toward the fix if you go ahead"). Customers like it, and it can help close repairs. But be honest about what it costs.

If you credit the fee, your repair prices must already cover the diagnosis. Otherwise you're doing the diagnosis for free on every job that closes. Run the numbers on your own close rate.

Example with made-up numbers: 100 diagnostic calls in a month at $165. Say 60 customers approve a repair and 40 decline.

No credit: fee revenue = 100 x $165 = $16,500.
Credit on repair: fee revenue = 40 x $165 = $6,600. The other $9,900 has to come from your repair prices, or it's gone.

So the question isn't "credit or no credit." It's "where does the diagnosis get paid for?" Two honest ways to do it:

Keep the fee separate. Simple and clear: the fee pays for the diagnosis, the repair price pays for the repair.
Credit the fee, and build diagnosis time into your flat-rate task prices. When you set task times in your price book, include the typical diagnosis time. Our HVAC flat-rate price calculator works from task hours, so add the diagnosis portion to the hours there.

What to avoid: crediting the fee and pricing repairs as if the diagnosis were already paid for. That's the version that quietly shrinks your margin.

Also decide up front: does the credit expire (for example, only if the repair is approved on the same visit)? Does it apply to a system replacement? Put the answer in writing so nobody makes it up on the spot.

After-hours, weekend, and holiday premiums

An after-hours call costs you more than a daytime one, so the fee should be computed separately, not just "daytime fee plus a bit." Use the same steps, with the after-hours costs.

Example, made-up numbers:

Labor: the tech is on overtime at $45/hour ($30 x 1.5). Payroll taxes and comp scale with pay, but PTO and health insurance mostly don't, so say the burden on overtime hours is 20%: $45 x 1.20 = $54 per hour. If your policy pays a 2-hour minimum for after-hours call-outs, labor = $54 x 2 = $108.00.
On-call pay: you pay the on-call tech a $150/week stipend and average 5 after-hours calls a week. That's $30.00 per call.
Truck: $14.00, same as daytime.
Overhead: $60.00, same as daytime (or more, if you pay an after-hours answering service).

Break-even = $108 + $30 + $14 + $60 = $212.00. At a 20% margin: $212 / 0.80 = $265.00.

There's one more cost that doesn't show on paper: the tech's willingness to keep taking on-call weeks. Burning out your best tech on underpriced night calls is expensive. Some shops set the after-hours fee high enough that only true emergencies get booked at night, and offer the customer the first daytime slot at the regular fee as the other option. Offer both and let them choose.

Decide and write down:

What counts as "after hours" (for example, weekdays after a set time, weekends, listed holidays).
Whether members of your maintenance plan get a lower after-hours fee or priority scheduling.
Whether the after-hours fee is credited toward a repair, and if so, whether the full amount or only the daytime portion.

How to present the fee on the phone

The fee rarely loses a customer by itself. What loses them is saying it badly: sounding unsure, apologizing, or letting them hear it for the first time when the tech arrives. State it plainly, early, with what it includes.

A simple script for your CSR (adjust the numbers and policies to yours):

> "We can get a technician out to you [day/time window]. Our diagnostic fee is $[fee]. That > covers the trip and a full check of your system to find what's wrong. Before any repair work, the > technician will show you what they found and give you the exact price up front, and nothing > happens until you approve it. [If you credit it:] If you go ahead with the repair today, the > $[fee] goes toward it. Does that work for you?"

If the caller asks "can't you just tell me what it'll cost?":

> "I wish I could, but without seeing the system, anything I told you would be a guess, and we don't > want to guess with your money. The diagnosis is how we give you the real price."

If the caller says a competitor is cheaper or free:

> "I understand. What I can tell you is that our fee pays for a trained technician's time to find > the actual problem, and you'll get a firm price before any work starts. No surprises."

A few rules that help:

Say the fee on every call, before booking. Put it in the booking confirmation text or email too, if customers have opted in to messages.
Don't let the CSR discount it on their own. If you allow exceptions, spell them out.
Make sure the tech says the same thing at the door. Mixed messages cause most fee disputes.

Common mistakes

Copying a competitor's fee. Their drive distances, pay, and overhead aren't yours. Their fee may be losing them money too.
Pricing from the tech's wage, not the loaded cost. Taxes, comp, insurance, and PTO are real costs of every hour on the call.
Leaving out drive time. On a diagnostic call, the drive can be a big share of the tech's time.
Crediting the fee without building diagnosis into repair prices. You end up diagnosing for free on every job that closes.
Pricing after-hours as "daytime plus $50." Compute it from overtime, minimum call-out pay, and on-call pay.
Surprising the customer. A fee first heard at the door feels like a trick, even when it isn't.
Never updating it. Wages, fuel, and insurance go up. Recheck your fee at least once a year, the same time you review your price book.
Not tracking what happens after the diagnosis. If you don't know how many diagnostic calls turn into repairs, you can't tell whether crediting the fee is paying off. Our guide to HVAC KPIs every shop owner should track covers close rate and average ticket.

Checklist

What other shops charge to show up

Diagnostic fees and the phone scripts that go with them vary by shop, so bring yours to the Growth Room Discord for a second opinion.