Heating system timer

Manufacturer: (probably) Viessmann

Description of failure

The clock stops turning.

Failure investigation

Timers usually have an integrated battery that lasts a very long time, but simply runs out over the years. Unfortunately, soldered batteries are still very common. If possible, these should be replaced with an identical type. If the identical pinout of the battery is no longer available, it is also possible to order a vertical battery, solder it in on one side and connect it with a cable on the other side (as shown in the picture with the new green battery). This is a solid solution in the event of a repair.