Call tracking and attribution: how HVAC phone leads get counted, and miscounted

Three call signals that must stay separate

Google Ads documents three distinct ways of measuring phone leads, and mixing them is the most common reporting error we see.

1. Calls from ads. Calls placed straight from a call asset, a location asset or a call-only ad. Google's call conversion help says these need call reporting switched on, because they run through Google forwarding numbers.
2. Calls from your website. A forwarding number replaces your business number on your site for visitors who arrived from an ad. The website call tracking help explains that these dynamically generated numbers show which keywords, ads and campaigns led to the call.
3. Taps on a number on a mobile site. A click event, measured separately. It tells you someone tried to call, not that a conversation happened.

If a report adds taps to connected calls, every tap that ends in a real call is counted twice. Pick connected calls as your primary conversion and keep taps as a diagnostic.

Minimum call length: the quiet setting that changes everything

Both call types above count as conversions only if they last at least the minimum length you set. Google's pages do not state a default here, so check what your account uses.

How to choose a threshold (illustrative approach):

• Export a month of call durations from the call details report.
• Listen to a sample of short calls. Where do real enquiries start?
• Set the threshold just below the point where most real leads begin.

Too low, and wrong numbers and robocalls count as leads. Too high, and quick "can you come today?" emergency calls disappear, which in a January cold snap may be your most valuable calls.

Why dynamic numbers can break things

The website call tracking help warns that dynamic number insertion and third-party call tracking can stop Google verifying your number automatically, and that Google Tag Manager is not recommended for the phone snippet in that case. If you use a third-party tracking provider as well, decide which system owns the number on each page. Two scripts swapping the same number create gaps that look like a drop in calls.

There is also a local-search angle. Keep your real business number on your Google Business Profile and in your site's visible footer text, so your name, address area and phone stay consistent everywhere.

Choosing an attribution model in GA4

GA4 currently offers three reporting attribution models, according to Google's attribution overview:

The same page says first-click, linear, time-decay and position-based models stopped being available in November 2023, and that direct visits get no credit unless the whole path is direct.

For a small HVAC company, the honest choice is usually paid and organic last click for weekly reporting, because it is easy to explain and stable. Data-driven attribution needs volume to be meaningful. Whichever you pick, do not switch models to make a month look better.

Remember too that GA4 key events and Google Ads conversions are related but not identical. You can create an Ads conversion from a GA4 key event, and Google says Ads conversions do not appear in standard GA4 reports.

The reconciliation habit

Once a month, put three columns side by side:

• calls Google Ads counted
• calls GA4 recorded as key events
• calls your office logged, with the outcome (booked, quoted, not a lead)

The gaps tell you where measurement leaks. If the office log shows 60 real leads and Ads claims 90 (illustrative), something is double-counting. If Ads shows 20 and the office logged 60, most of your calls are arriving through channels you are not tracking, often organic search and the Business Profile.

The next step is to send booked jobs back to Google Ads, covered in Google Ads experiments and offline conversions. To find out whether those ads are creating new demand at all, read holdout tests. Questions? Call, text or email, or see the FAQ.