To ignite a frozen boiler, first shut off the system and allow it to cool. Use a hairdryer or space heater to warm the thermostat area. Check the pressure valve; if stuck, gently tap it with a tool. If the boiler remains unresponsive, contact a licensed technician. Always prioritize safety by avoiding open flames near water lines.

Freezing occurs when water inside the boiler loses pressure, typically due to a faulty pressure relief valve or outdoor temperature drops below 20°F (-6°C). According to the U.S. Department of Energy, 80% of frozen boiler incidents result from low pressure, often caused by insufficient insulation or valve malfunctions. The American Boiler Manufacturers Association reports that improper heating methods, such as using torches, can cause internal pipe damage, increasing repair costs by up to 40%. A 2022 study by the EPA found that 65% of DIY attempts to thaw frozen boilers lead to additional complications, including water leaks and electrical hazards. The average cost of professional repairs is $500-$1,200, compared to $300-$800 for timely maintenance. Regular maintenance, including pressure checks and insulation upgrades, reduces freezing risks by 70%, as cited by the National Board of Boiler and Pressure Vessel Inspectors. Always follow manufacturer guidelines and local codes to ensure safe operation.