My boiler won’t start – what to do first!
Nothing can be more frustrating than a non-functioning boiler on a cold day. Fortunately, noticeable changes in boiler performance proceed most mechanical failures. If you notice a change in boiler performance such as new noises, smells, rising stack temperatures or continually resetting safety devices, call your boiler professional for help.
Although unexpected mechanical failures do occur, it is likely that one of the boiler safety or operational devices is preventing your boiler from starting. Most safety devices have manual reset buttons that need to be reset before boiler operation can continue.
Continual resetting safety devices is an indication of unsafe operating conditions. Prompt attention by your boiler technician is required.
Locate all devices that can prevent your boiler from starting. They include:
Burner controller: The controller is usually located in front of the burner. On a call for heat the controller starts a sequence of events that ensure safe operation before the burner is allowed to start. The controller continues to monitor burner operation while the boiler is running. If for any reason the controller senses an unsafe operating condition it will shut the burner off. Pushing the manual reset on the controller will often restart the boiler.
High pressure or temperature switch: This device is a safety backup to the "operator" control. It has a manual reset which when pressed to start the boiler indicates that the "operator" control has failed.
Gas pressure switches on the fuel train: The natural gas fuel train usually has two pressure switches. The low-pressure switch locks out the boiler when too little gas is available for operation. The high-pressure switch locks out the boiler when the regulator is allowing too high a gas pressure. Both switches have a manual reset.
Low water cutoff: The low water cutoff may have a manual reset. When reset indicates a low water condition existed in the boiler.
Other devices that may prevent the boiler from starting:
Time clocks: Time clocks or other energy management devices may restrict boiler operation during weekends, evenings or other times of the day. Check their operating schedule.
Outdoor temperature limits: These devices sense outdoor temperatures and prevent boiler operation above certain outdoor temperatures, usually 65 degrees.
If resetting these devices does not start your boiler call your boiler professional for assistance.
Reminder: Do not bypass any safety devices in an effort to start your boiler.
