Boiler Operation, Service, and Maintenance
Always follow the manufacturer’s instructions for boiler operation, service, and maintenance. These instructions are commonly contained in the owner’s manual left with the boiler by the installer. If you do not have these instructions, you should contact the local dealer for advice or write to the manufacturer.
The sections that follow contain recommendations for operating and maintaining boilers. Because many of these recommendations specifically pertain to either steam or hot-water space heating boilers, they were divided and listed accordingly.
Note
All service and maintenance work must be performed by those trained in the proper application, installation, and maintenance of plumbing, steam, and electrical equipment and/or systems in accordance with all applicable codes and ordinances. If available, the boiler manufacturer’s service and maintenance instructions should be followed
Safe and Reliable Boiler Performance
Poor boiler performance and unsafe operating conditions are caused by failure to follow proper maintenance procedures, the existence of low water conditions, the use of outdated or damaged safety devices, or operator error. The following rec- ommendations will go a long way toward providing trouble- free boiler operation:
• Always follow the ASME code maintenance standards.
• Maintain an inspection and maintenance log for the boiler.
The log should include the date and specific form of main- tenance performed.
• Always follow the boiler manufacturer’s operating instructions for initial setup and startup.
• Never use outdated controls. Many will have a date code stamped on them. Replace the control if its age exceeds the stamped date.
• Always operate the boiler with code safety relief valves.
• Always use safety relief valves rated for the boiler.
• Never bypass the existing boiler controls.
Caution
To prevent serious burns, always allow the boiler sufficient time for its temperature to cool down to at least 80°F (27°C) and for its pressure to drop to 0 psi (0 bar) before servicing. Drain the boiler to a level below that of the lower gauge glass tapping on the low-water cutoff control.
Caution
To prevent electrical shock, always shut off the electrical power to the boiler before making any electrical connections.
Steam Boilers
Operating and maintaining a steam boiler differs in certain respects from the procedures followed for hot-water space heating boilers. Many of these differences are evident in the recommendations that follow.
1. Keep a steam boiler filled to the water level recommended by the manufacturer when not in use.
2. Check the water level in the boiler before starting it. The heat- ing surface can be damaged if the water level is too low.
3. Keep the water level at the center of the water gauge glass during operation. If the water level is too low, use the manual feed valves to add more water. These valves are found in most systems.
4. Always add water to the boiler gradually. If at all possible, avoid adding water to a hot boiler. Never add water to an operating cast-iron boiler. Cold water fed rapidly into such boilers may come in contact with the hot surface of the cast-iron heat exchanger, causing it to crack. Shut off the boiler and wait until it has cooled down before adding water. After the boiler has had sufficient time to cool, slowly add water through the cold-water feed line.
5. Check the low-water cutoff at regular intervals. Sediment or rust accumulating under the float of the low-water cutoff can cause it to malfunction. As a result, a drop in the boiler water level would not register properly.
6. Check all boiler accessories to make certain they are functioning properly. Movable parts should be inspected and oiled regularly.
7. Never allow a low-pressure steam boiler to exceed the upper safe pressure limits recommended by the manufacturer (usu- ally 3- to 4-lb of pressure).