Why the gas water heater didn't work. Secret batteries

The situation turned out to be so ridiculous that I could not resist smiling, it happens.

Application

They call, they ask to come in, the gas water heater does not turn on, during the conversation it turns out that the batteries on it have recently been changed.

In our area, almost everyone has such speakers, they have one inconvenience, you need to change the batteries (every six months), there are plus, if the "light" is turned off, there will be hot water, such a water heater does not need to be protected by an RCD, as with a network connection.

I estimate maybe installed incorrectly, but this is unlikely, since the column has been with the owners for a long time, and there were no such problems before. I decide for myself that most likely sold expired batteries, I take a multimeter with me.

I open the compartment and see such a picture, a plastic cap is put on the positive contact, apparently additional protection against short circuits during transportation, naturally, there is no contact.

How to check correctly

Clearly, it is necessary to remove the caps, at the same time I decided to check, it was not for nothing that I was dragging the device.

Once asking the seller if the batteries were working, he saw that he took out a multimeter and began to measure the voltage, as it turned out, this is a common mistake, need to measure amperage.

I moved the probes to 10A, one battery showed 3.4A, and the other 3.7A, not a fountain for new ones, but within normal limits. The column starts to screw up when the value drops below 2 A.

In general, I installed it, removing the protection, everything worked, you just have to be careful!