UVC illuminant T5 Orange base 40W for Jumbo Tech UV-C F980002
Replacement lamp for Jumbo Tech UV-C
Every UV-C illuminant loses power over time and also due to switching on and off. Therefore, it makes sense to replace the bulbs every 1-2 years.
In any case, you should check in spring whether the UV-C is still working and whether the quartz glass is dirty / calcified.