Shelly 2.5 channel 2 overheating

Hello everyone

I searched the forums and didn't find an answer for my problem. I am using a Shelly 2.5 to control 2 heating resistors. On channel 1 I have a 800W resistor and on channel 2 I have a 1200W resistor.

When I turn on channel 1 in the shelly app, the relay immediately turns on, the button turns blue and power info is immediately shown. After a short time, the inner temperature sensor reading stabilizes at around 77ºC

When I turn on channel 2 in the shelly app, the relay immediately turns on, but power info and the blue button only appear after 5 or 6 seconds. The inner temperature sensor reading starts rising and, after less than 5 mins, it overheats at 95ºC. It's unusable.

1200W at 220V ~= 5A, which is about half of what it should be able to handle.

I have tried rebooting it, factory resetting, but nothing changed. I am starting to think it might be faulty.

Any help / comments are appreciated. Thank you in advance.

I have attached the wiring diagram.

Thank you for your answer. I did just that, bought 2x Shelly 1PM and it works fine: ~65ºC at 5A.

It annoys me that Shelly 2.5 can only handle a few Amps, when it advertises 10A...

I am new to Shelly but i concur with Olsche based with my very limited experience:

- Shelly 2.5 is mounted on a DIN rail between a module and the plastic case in a basement at 13C. So poorly ventilated but not a hot place.

- Channel 1: 11W

- Channel 2: 35W

- Reported (internal) temperature stabilizes at around 67.5C.

I did not even dare to try a Shelly 2.5 on a more hungry circuit (400W+500W): i will use a Shelly 1 instead. I am not so much worried about a fire hazard but more about the life expectency of the device.

I do not mean to be negative because i really love the devices for many reasons but i think that the documentation should be more explicit about the recommended sustained usage range vs the 'technical' upper limit because the 300W mentioned by Olsche is a long way from the 2200W+ (10A). Personaly when i first read the specs, i assumed that 50% (aka 1100W) would give plenty of margin but that does not seem to be the case.