Why did the voltage regulator keep clicking?

Question

Electronics

This morning, the TEPLOCOM ST-400 voltage stabilizer for a gas boiler began to click. Clicks at intervals of several seconds (relay switches). Its warranty has already expired. What could be the problem?
Video attached

Answer 1

Previously, they were treated by photography, now - by video ... Possibly poor power supply in the network, perhaps the device itself is dying.

Answer 2

What is there to be surprised. Most of the stupid logic. Up to 237v for straight lines, 238v is already turned on and the output voltage drops to almost 203v. And the question is what will the unit die faster from? From jumps 2-3v 237-239v or from jumps> 20v 203-237v? When it starts to click often, I just advise you to take a multimeter and see what is happening in the outlet. Perhaps just small fluctuations of 2-3 V at the threshold of operation ...
And in general, it is dangerous to leave such things unattended. I had a Uniel. About 3 years ago I took it for 3.5 k. After a week of work, I caught some kind of corral and the scoreboard began to show the voltage incorrectly, then once I turned off the output and started to warm up wildly, it melted decently, it’s good that at that time I was at home ...