7 Money Leaks That Quietly Shrink an HVAC or Plumbing Business
Sam's List Editorial | 2026-07-28
7 Money Leaks That Quietly Shrink an HVAC or Plumbing Business A mechanical contractor doing 3 million dollars a year with eight trucks can be working harder than any competitor in the market and still land at a 4 percent net margin. Not because the pricing is wrong. Because seven small leaks compound. None of these show up as a line item called "problem." They show up as a bank balance that never matches how busy you were. The most common HVAC business bookkeeping mistakes are all in this category: quiet, structural, and completely fixable once someone counts them. 1. Truck Stock That Never Makes It Onto an Invoice Every service van is a warehouse with no inventory controls. Fittings, capacitors, contactors, sections of line set, a spare condensate pump. Material gets pulled for a job, and roughly none of it gets tracked back to that job. The leak is not theft. It is the 40 dollars of parts on a call that got invoiced at a flat diagnostic rate, forty times a month, across eight trucks. That is real money, and it never appears anywhere except as a cost of goods sold number that runs higher than it should for reasons nobody can name. The fix is unglamorous: material gets assigned to a work order before the tech leaves the site, and truck stock gets counted on a schedule. The limitation is that no system survives contact with a busy Friday if it takes more than about thirty seconds per job, so the process has to be built for the tech, not for the bookkeeper. 2. The Loaded Labor Rate You Are Not Actually Using You pay a tech 32 dollars an hour. You are not paying 32 dollars an hour. Add payroll taxes, workers compensation at trades rates, health coverage, paid time off, the truck, fuel, insurance, the phone, the tablet, licensing and continuing education, and the tools. Depending on your market and your benefit structure that 32 becomes something closer to 50 or 55. If your quoted price is built on the wage instead of the loaded rate, every job is thinner than your estimate said. Calculate the loaded rate for each tech class once a year and rebuild your pricing on it. The caveat: a loaded rate is only as good as the allocation behind it, and allocating a truck cost across too many billable hours produces a comfortable number that is also wrong. Which brings up the next leak. 3. Effective Billable Hours Per Tech Per Day This is the number that decides whether the pricing model works, and most shops do not compute it. A tech on the clock for eight hours does not bill eight hours. Subtract drive time, the supply house run, the truck load-out, the callback...
