The topic was “Shelly 2.5 getting hot to touch (63°C external case) - should I be worried?”
How is my reply not appropriate to the topic?
Its not “not appropriate”. It just has nothing to do with the actual (internal) cause. Living in the dessert with shelly would also raise the temperature 
. Have you read the topic now?
I rest the case 
.
Exactly as Jonah1970 — mine is also in a big pattress box in the airing cupboard.
I suspect the internal temperature is related to the power sensing circuitry. It’s probably done by sensing voltage across a very low value resistor in series with the load, which heats up due to I²R power dissipation.
In case anyone needs it I am attaching my automation that controls the water heater (via a Shelly 1PM) during cheap electricity tariff times. I also have a momentary 1 hour boost function and have incorporated the suggestion from @Troon to wait until the heater turns off via its own internal thermostat before turning the Shelly off.
alias: Immersion Heater Control
description: ''
trigger:
- platform: time
at: input_datetime.immersion_on_time
id: turn_on
- platform: time
at: input_datetime.immersion_off_time
id: turn_off
- platform: state
entity_id: switch.immersion_boost
id: boost
condition: []
action:
- choose:
- conditions:
- condition: or
conditions:
- condition: trigger
id: turn_on
- condition: state
entity_id: switch.immersion_boost
state: 'on'
- condition: state
entity_id: binary_sensor.home_occupied
state: 'on'
sequence:
- type: turn_on
device_id: a13f327b4f69116da77dcfb62fa8bea3
entity_id: switch.water_heater
domain: switch
- delay:
hours: 0
minutes: 30
seconds: 0
milliseconds: 0
- wait_template: '{{ states(''sensor.water_heater_power.state'') | float < 10.0 }}'
continue_on_timeout: true
timeout: '02:30:00'
- conditions:
- condition: or
conditions:
- condition: trigger
id: turn_off
- condition: state
entity_id: switch.immersion_boost
state: 'off'
sequence:
- type: turn_off
device_id: a13f327b4f69116da77dcfb62fa8bea3
entity_id: switch.water_heater
domain: switch
default: []
mode: restart
Perfect! Thanks for the reply.
Finally I ordered one, it arrived yesterday and I just installed it today above the waterheater, “inside it”, in its plastic box where all the electric connections are. It was the easiest quick solution to install it, without touching anything else and just adding 2 electric wires of 10cm each.
So far so good, it seems to work, I’m currently playing with the Shelly app, and soon some geek stuffs using HA
Hey,
I also have a Shelly 1 PM Plus and I’m also wondering why I do not see its own internal temperature.
I’m not yet on HA, but there is not such information on the Shelly app. On some screenshots or videos it can be seen that the temperature is displayed for Shelly 1 PM (the “old” version)
Did you manage to see it?
Yes, the internal device temperature is presented to HA using the HA integration.
Just did the HA integration, maybe i’m a little bit blind, but there is no sensor for internal temp (?)
There are binary sensors “ok/nok” for overheating etc, but nothing for really sense the heat in °C
maybe I did something wrong in HA?
Well, I found it, it was deactivated
I just enabled the entity status and it works!
So finally, I wired the Shelly 1PM Plus with the “insecure” manner, but it did its job over the two last nights. Here is what happened:
On the paper my whaterheater is a 12A, I expected a consumption of 2800W, Shelly says 2600. When it’s not heating the Shelly’s internal temp is ~45° and ~72° when the heater is on.
As far as understood, I feel quite safe to be “so cold” compared to the max load and temp the shelly is designed for.
So far so good.
I noticed that periodic disconnections between the Shelly and HA occur (something like 10 sec of unavailability every couple of minutes), it’s the unique sensor, among several dozen I have, acting as such. I don’t really matter, just that curves are discontinuous and ugly
Thank you again for the support!
Tiny update from my side, I just installed the latest beta firmware (20220512-132555), and it seems that the idle Shelly’s temperature dropped a lot: 26.6°C, which is just +4°C above the room temperature
@r-jean-pierre How do you go about installing a beta version of the firmware? I have only had my Shelly 2.5 up and running a couple of months
Just to get the math right
The power dissipated in a bad connection like 1 ohm is not resistance times voltage
You can either calculate it as P = V2/R where V is the voltage over the connection.
Or P = R * I2 where I is the current in Amps running through the connection.
The voltage over the 1 ohm connection is not 120 V unless the connection shorts the mains.
But that said. 1 ohm and 12 A current is 144 W in a small bad connection. That will be enough heat in a spot to put a house on fire. It is really important to keep connections super tight. Especially when dealing with high currents. And that goes for both 120 V and 220-240 V circuits
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Well actually, i don’t really remember exactly what I did step by step, but in the web version of the shelly (its @IP in a webbrowser) i could see, that a beta was available:
I just had to press the blue update button, and this is how i got the 0.10.2-beta1 (which was probably released last Thursday according to the firmware build ID). Maybe it’s possible from the android application or HA integration, I suppose it’s a coincidence that this beta firmware was released just exactly when i was toying with the webapp
To conclude, I said that the idle temp dropped quite a lot, but i can confirm that also the inload (2.6kW) temp:
Before the beta, I was twice >70°C, and after the beta update, around 53°C/55°C three times in a row.
Seems that both temperatures are cooler (almost 20°C less)
Is this confirmed that 0.10.2 (which is now stable) improves somehow temperature of devices? I have installed it on all my 1PM and 2PM devices and internal sensor readings does not differ at all.
I have also notices two thins:
- 1 gen devices in general work on lower temperatures (I have shelly 2.5 and dimmer 2)
- For the same model differences of internal temperatures with no load differ even by 5°C
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I am using a Shelly1PM and a Shelly Plus1PM (newer model) to power a 3kW water heater and a 2kW water heater respectively.
It’s been about 4 months. They do get quite hot, as the Shelly device is stuffed into a small box.
Additionally, I have a Shelly Plus1 for switching about 20 watts of LEDs as well. Even that gets hot. Idle temp is is around 47 deg C. When lights are on, it can get up to 57 deg C.
That’s been running for two months.
These devices have the relevant AU/NZ certification, along with the CE/UL certifications. I wouldn’t worry too much about it honestly.
If they were failing and causing fires or something like that (like some of the SonOffs were recently) we’d be hearing about it for sure.
Has anyone ever installed a heat sink or fan to keep it from overheating? I’m also using a 1pm as a thermostat to heat a 3.2kw element and the device overheats after 20 mins
