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Note: Inspections of boilers and pressure vessels throughout Minnesota will continue during the COVID-19 pandemic. Prior to an inspection we will contact owners to schedule or reschedule the inspection. We will not attempt to perform an inspection in a facility where owner/management has immediate health concerns for residents or patients during the COVID-19 pandemic. For help with questions, contact your regional inspector


Do I need a boiler installation permit?

The installation of individual boilers or boilers connected to a common circulation manifold requires a permit if the individual or combined BTU input exceeds:

  • 100,000 BTUs for steam boilers;

  • 500,000 BTUs for hot water supply boilers; Not only a manifolded (1) 500,000 BTU/hour input must be exceeded, but (2) 120 degree F and a (3) nominal water capacity of 120 gallons; or

  • 750,000 BTUs for hot water heating boilers.

If your installation exceeds the above BTU inputs, you will need to apply for a permit.

Get a permit

Apply or pay for a boiler installation permit. Note:  A new permit system launched June 22, 2020. Users must create a new account and link it to their mechanical bond to obtain and pay for permits.

Installer requirements

Mechanical contractors are required to file a $25,000 mechanical contractor bond to contract to perform gas, heating, ventilation, cooling, air conditioning, fuel burning or refrigeration work in Minnesota. The bond must be on a form approved by DLI and written by a surety company licensed to do business in Minnesota. View more information about mechanical bonds.

Inspection requirements

All boiler installations require a hydrostatic test applied to the boiler. The test pressure should be approximately 75 percent of the safety valve set pressure. Example: 15 psi safety valve set pressure, 11 psi hydrostatic test pressure. The test pressure must hold for at least 10 minutes.

All boilers are subjected to an operational test of all boiler controls. View the checklist used by inspectors.

Questions?