12 Proven Procedures to Layup a Boiler

multiple large attached boilers in a room

Laying up your steam boiler or heating boiler can help prevent corrosion and scale. This is done in addition to the normal chemical treatment program. Additionally, even the best chemical treatment program must be supplemented during the non-operating, or lay-up cycle to prevent corrosion. When your boiler is taken off-line and allowed to cool down, special chemicals must be added at much higher levels to offset the increased level of available oxygen. This is important because oxygen can quickly produce pitting in both boiler tubes and tube sheets. Furthermore, once a pit develops it can corrode completely through a tube in a matter of days, and require costly repairs.

Updated March 24, 2022

Determine how Long the Boiler will be Shutdown

Choose a wet or dry layup based on the length of time that you intend the boiler to be shutdown.

  • Short Term (5-10 days)
    • Use wet layup
  • Medium Term (10-30 days)
    • Use wet layup
  • Long Term (30+ days)
    • Use dry layup

Our expert service technicians perform wet and dry layups for any length of time. To get help from an expert click here to message us


Wet and Dry Layup Procedures

Service technician checking boiler system

Wet Layup

1. Fill the boiler with water that is 180°F or hotter to drive off dissolved oxygen

2. Add the recommended treatment chemicals until the alkalinity of the boiler water is at or above 400 ppm and the sulfite is above 200ppm

3. Button-up all inspection ports, fill the boiler to the top of the steam header, while vented. Then, seal the header

4. Circulate water a couple of times a month, allowing the chemicals to blend to treat all surfaces

5. Test the system water regularly and add additional chemicals as needed


Dry Layup

6. Blowdown the boiler before draining

7. Open a vent. Once the water temperature is less than 140°F and the boiler is at 0 psi, drain the boiler and allow it to dry thoroughly

8. Open and clean the fireside. Keep the boiler warm as the melted, wet soot will be much easier to remove than the cooled, dry soot

9. Dry the fireside with a heater or fan

10. Open and clean the waterside. Close the gate valves near the vessel and keep the manhole top open

11. Examine internal and external surfaces. Inspect for leaking and cracking. Swab the fireside with neutral mineral oil for corrosion prevention

12. Consider further protection can be achieved through the use of desiccants, sorbents, or our recommended Boiler Lizard®


Learn More About Our Boiler Treatment Services


To talk to an expert about boiler layup or other technical matters, call one of our Technical Support Team Members at 888-486-9263 or click here to message us

Portrait of Matt Welsh, the co-president
Matt Welsh
Vice President, Water Consultant at Chardon Labs | Website | + posts

Matt Welsh is the Vice President and Water Consultant at Chardon Labs.  He helps consult a wide range of customers utilizing various methods of water treatment, from chemical to chemical-free approaches, large and small applications, and across a wide range of geographical influences.  With 20 years of water treatment experience, including a wide range of troubleshooting and service in potable water and non-potable HVAC and industrial applications, he is an expert in water treatment chemistry for cooling towers, boilers, and closed-loop systems.


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