Anyone quoting you a single cost-per-lead figure for HVAC is selling something. The number varies enormously by market, by season, and by whether you are chasing emergency repairs or planned installations. What follows is how to work out your own number rather than trusting someone else's.
Start from what a customer is worth
Not what a job is worth — what a customer is worth, including the maintenance visits and the referrals. If a service customer is worth several hundred dollars over two years, you can afford a lead cost that would look alarming against a single call-out fee.
Then work out your close rate
If four in ten enquiries become jobs, you can pay four times more per lead than someone closing one in ten. Most businesses have never measured this and are guessing at the number that determines everything else.
Seasonality changes the maths
In a hot market during peak season, competition for emergency repair searches gets fierce and costs climb. The same keyword in the off-season can cost a fraction of that. Annual averages hide this completely.
The number most people get wrong
Cost per lead is not the metric that matters. Cost per acquired customer is. An expensive lead source with a high close rate beats a cheap one full of tyre-kickers, and only tracking will tell you which is which.