Class code 5537: HVAC, refrigeration and ductwork installation and service

By Adrian Middleton, Sword & Shield, PLLC · Updated Saturday, October 24, 2026

What code 5537 covers

• Installation, replacement, service and repair of heating, air conditioning and refrigeration systems and equipment.
• Ductwork fabrication on site and installation, including insulation of ducts by the HVAC crew.
• Thermostat and control wiring performed by the HVAC crew.
• Technicians, installers, helpers and drivers.

What it does not cover

• Sheet metal shop fabrication (3076) with separate records.
• Plumbing (5183) performed by a separate crew.
• Electrical wiring beyond the equipment connection (5190).
• Clerical and outside sales (8810, 8742) for employees who do nothing else.

How the Division assigns it on a stop-work order

On a stop-work order worksheet, the investigator assigns a class code to each uninsured worker for each period from two sources: the employer's records (payroll by job, job descriptions, invoices, permits) and the investigator's own observation on the jobsite. With no records, Rule 69L-6.028 directs the Department to impute payroll at the highest-rated class code the investigator observed. Vans, condensers, line sets and duct board identify the crew. The worksheet issue is headcount: technicians, installers and helpers paid as independent contractors are employees, and 'sales' technicians who also install are 5537 for all hours. Under the NCCI basic manual the governing class is the one with the most payroll, and an employee's payroll is assigned to a single code unless the records separate it by operation; interchange-of-labor splits require contemporaneous payroll records, not after-the-fact estimates. Getting a worker moved from code 5537 to a lower-rated code is a records argument, made line by line on Form DFS-F4-1595.

HVAC contracting is licensed under Chapter 489. Section 440.107(14) requires the Department to notify DBPR of the order. See licensed contractors and the DBPR referral.

Misclassification patterns the investigator looks for

• Install crews paid per system and called subcontractors: employees under s. 440.02(18)(c), plus the misrepresentation penalty.
• Comfort advisors coded 8742 who also run service calls: 5537 for all of their payroll.
• Seasonal helpers paid cash during the summer rush: employees, and the pattern the fraud unit looks for.

Clerical (8810) and outside sales (8742) are standard exception codes. A worker's payroll goes there only if their duties are exclusively clerical or sales and the records show it. An office manager who also runs materials to the jobsite, or an owner who sells jobs and swings a hammer, is assigned to the governing construction class for all of their payroll. This is the single most common reclassification on a penalty worksheet.

The rate

Florida's approved manual rate for this code is filed by NCCI and approved by the Office of Insurance Regulation effective each January 1. The Department's worksheet uses the rate in effect for each period of non-compliance, so a 24-month lookback can span three rate years. Rates are not stated on this page because they change; your agent, carrier or the current NCCI Florida rate pages have the figure. The free calculator takes the rate as an input.

Questions