What boiler means
A boiler heats water, or makes steam, and circulates it through pipes to radiators, baseboard or floor tubing to heat a building.
Where it matters on a HVAC job
Boiler replacement is often bigger than the box: venting, near boiler piping and controls usually change too. Walk the system before quoting, and include what the new boiler needs to run as designed.
What the model code says
- The code defines a boiler by its limits: water pressure not over 160 psig and water temperature not over 250°F. (IRC 2021, Chapter 2)
Check which code edition your building department enforces for boiler before you quote.
What it costs
Jobs that involve boiler are priced in the boiler replacement cost guide: about $6,000 typical, usually $3,650 to $9,250. The guide shows its sources and what moves the price.
Work it out
- Cost guide: Boiler replacement cost
- Licensing: HVAC license rules by state
- Tools, templates and guides: Free HVAC resources
Sources: 2021 International Residential Code, Chapter 2, Definitions (ICC). Checked October 9, 2026.