How Often Should a Boiler be Inspected? (+ More FAQs)

How Often are Boiler Inspections

It’s important for boiler owners and operators to establish a regular inspection schedule for their equipment. How often your boiler should be inspected depends on a variety of factors, but there are general guidelines that can help you develop an appropriate plan. 

Knowing when to have your boiler checked can help ensure its safe and efficient operation. Note that boilers can fail at any time, which could lead to a major catastrophe or injury; the only insurance against this is a proper maintenance and inspection program carried out by an experienced service partner. This article will discuss the ins and out of boiler inspection.

How Often Should a Boiler be Inspected? 

A boiler should be inspected at least once a year. The date for this inspection should be documented in your boiler log book. For High-Pressure Steam boilers, internal inspection is required by state code, and your boiler insurance provider or local authority having jurisdiction may have additional requirements.

How often should a boiler be inspected

Though you can inspect your boiler any time of the year, for proper tuning, you will need to provide enough load to operate the boiler throughout its firing range.  For this reason, on hot water boiler systems, it can be best to inspect a boiler during cold weather, ensuring proper tuning after the service. 

You might also consider scheduling an additional combustion tuning service at a later date. Most boiler inspectors look for corrosion, signs of damage to the boiler’s tubes and tube sheets, welds, leaks, and soot build-up. The following are some things that are checked during a boiler inspection: 

A thorough inspection should include;

  • Boiler cooled and offline
  • Boiler isolated from steam, water, and electrical
  • Hydrostatic testing of boiler and piping prior to draining of the boiler
  • Drain boiler and open and inspect the boiler’s fire and waterside
    • Fire Side
      • Open Front and Rear Doors
      • Remove Rear Access Plug
      • Brush Flues
      • Vacuum all surfaces
      • Wash coat refractory and surfaces (as needed)
      • Replace all gaskets and close unit
    • Water Side
      • Flush loose scale
      • Remove low water cut-offs and clean
      • Remove and replace gauge glass and gaskets 
      • Remove equalizer plug 
      • Replace all gaskets and refill with water 
      • Torque door bolts & waterside plates to customer specs
    • Safety Circuit Checks
      • ASME operational steam down testing for LWCO, Auxiliary LWCO and
      • Low Water alarms
      • Flame Scanner test
      • High and low fuel pressure switches
      • Operational control limits
      • High limit controls
  • Reset combustion (on all fuels)
  • Remove debris generated
  • Re-tighten all Waterside and Fireside bolts once the boiler is up to pressure, per manufacture spec.
  • Complete Service Documentation, including a 50-Point Boiler Safety Check List and photos of any deficiencies, along with recommendations to correct deficiencies

Why Should a Boiler Be Inspected? 

There are many reasons why you should have your boiler inspected. However, the main reason is to ensure the safety of your employees, customers, and guests. Other reasons include: 

Why should a boiler be inspected
  1. To identify any potential problems with the boiler and fix them before they become more significant problems
  2. To increase the lifespan of the boiler 
  3. To ensure the boiler is in optimal condition 
  4. To reduce energy costs by ensuring the boiler is running efficiently and safely. Inspections increase efficiency by tuning the burner for complete combustion, with minimal excess air (reducing stack losses), and by cleaning scale from the fire and water sides of your boiler. Per a US Department of Energy study, as little as 1/32” of scale can increase fuel use by 2% or more, depending on the composition of the scale. 
  5. To reduce your liability should something unsafe happen while operating a boiler. For example, if a boiler’s safety devices are not working properly, it could allow a situation where the boiler can operate in a low water condition or above its design pressure, creating the risk of serious injuries or death. Inspections by qualified personnel provide crucial, additional tests of your boiler’s safety devices, above and beyond the routine daily checks.

How do I prepare a boiler for inspection? 

The best way to prepare for an inspection is to ensure that you have all necessary documentation on hand, such as your boiler logbook, maintenance records, and test results. You should also make sure that the area around the boiler is clean and clear so that the inspector can easily access the unit. 

how do i prepare a boiler for inspection

Additional steps include: 

  • Make sure there is access to all parts of the boiler 
  • Make sure the boiler is turned off and cool to the touch 
  • Remove any debris from around the boiler 
  • The boiler should be isolated from fuel, electricity, steam, and water (lock-out-tag-out)
  • The boiler should be drained and opened on both the fire and waterside prior to the inspector’s arrival

After inspection, the boiler will be regasketed, closed, filled, safety devices checked, restarted, and combustion tuning will be performed.


How Long Do Boilers Last? 

This question can be challenging to answer because it depends on various factors, such as how often the boiler is used, the quality of the boiler, and how well it is maintained. However, well-built industrial boilers should last 30-years or more with proper maintenance. 

How Long Do Boiler Inspections Take? 

The time it takes to inspect a boiler depends on the size and complexity of the system.   It is important to take into account the length of time it will take your boiler to cool, a day or more for a large steam boiler, and add time to drain and open, onsite time for the inspector, plus closing, filling, and combustion tuning – plan for a 1-2-day process, from start to finish.  Smaller, low-pressure steam, or hot water boilers requiring an external inspection that can be performed in a day or less.

Is it a legal requirement to have a boiler inspected? 

Yes, depending on your local and state laws it is required to properly inspect boilers on a routine basis. It is important to consider the inspection requirements according to your insurance provider.

 The requirements vary depending on the type of boiler.  Beyond the legal requirements, you should consider the benefits of additional preventive maintenance services, they can be biannually, or quarterly, depending on the needs of your facility. 

What Are the Safety Devices on a Boiler? 

There are many safety devices on a boiler. Some main examples include water level monitoring devices (Low Water Cutoffs), temperature/pressure controls (modulating, operator, and limit controls), flame scanners, gas pressure switches, combustion air pressure switches, safety relief valves, and more.  Which safety devices are included on a boiler is dictated, at a minimum, by code requirements and insurance requirements, based on the type and size of the boiler.  

The Bottom Line 

It is important to have your boiler regularly inspected to ensure its safe operation. The inspector (and your service provider) will look for any problems with the unit and make sure that it functions within the safety parameters. They will also check the condition of key safety devices on the boiler. The time needed for the inspection varies. You should prepare for the inspection by ensuring that you have all necessary documentation on hand and that your boiler is accessible, cool, and open prior to the inspector’s arrival. 

W.C.Rouse can help with your next inspection by ensuring the boiler is open and ready for the state inspector, correcting any deficiencies found, closing, and retuning your boiler after inspection. We pride ourselves on providing the best customer service in the boiler industry. Contact our team of service technicians who are well trained to help you with your preventative boiler maintenance, inspection, and turn-ups. 

Jeff Lawley

After graduating from Florida State University with a B.S. in Mechanical Engineering, Jeff Lawley headed up the engineering department at Schaefer Interstate Railing. A few years later, he took an Engineering Sales position here at W.C. Rouse & Son, and over the next 8 years, he worked his way up to the position of President of the company.