De Dietrich 95340248 fuse 3.15 AT

This article is a fuse, designated 3.15 AT, from De Dietrich. Such fuses are installed in the control circuit of a boiler or burner to protect the electronic control board and low-voltage wiring from overcurrent. They are typically located on the main control box or within a fuse holder on the terminal strip. When a fuse blows, the system will fail to start or will lock out without any obvious error code on some controllers. Selection is based on the required current rating and physical size (cartridge type, blade type, or cylindrical); the marking 3.15 AT indicates the rated current and characteristic. Always replace with an identical rating to avoid damaging the control board or compromising safety. Because a blown fuse often results from a shorted component (such as a fan motor, solenoid valve, or igniter), it is good practice to check for the root cause before fitting a new fuse, otherwise the replacement may blow immediately. If the fuse is intact but the system is dead, check for poor contact in the fuse holder itself—corrosion or loosening can mimic a blown fuse.