Underfloor heating project for a HA Newbie

Hopefully you’re still here. I’ve got a question. I’m trying to accomplish basically the same, as you do. Furthermore, I have 12 x 24V Actuators already installed into a pretty dump zone regulating system. I have bought an ESP 8266 development board with 16 relays. Also bought a power adapter outputting 1.5A with 24V. I have hooked up the wires to the board, and it starts booting up. The Wi-Fi starts transmitting, and I can connect to it. Cannot program it, I’ve just ordered a UART to USB connector for that, but that’ll work out.

What I don’t get is how to wire the board and the relays. I assumed the 24V adapter is powering both the relays as the board itself by only using the 2 connector pins. However, looking at your wiring scheme, you have a separate live line and neutral line connected to all the relays. All the relays are innerconnected with a wire on the current. Does that mean if one relay does not have a current, then it is just offline?

Hi Martijn,

my setup is slightly different from yours in the sense that my actuators are 230VAC.

Therefore in my installation I have a 230VAC-to-5VDC PSU that I use to power supply the digital part of the ESP-board. The 230VAC power is only supplied to the relays so that they can feed the power onto to the actuators.
In my relay boards each relay has 3 terminal screws where you connect the hot wire in the middle and the actuator to the left side. (The terminal screw to the right (which I don’t use) carries inverted logic so that it is hot when the signal is off.)

Good luck with your project, I hope you are successful and have fun at the same time!

BR David

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Thanks! So in my case, since everything is 24V, I need to split the signal and connect every relay with the hotwire in the middle too. Let’s see what happens :wink: Thanks for your reply.

I’m now stuck at being able to programming the ESP12F. Any pointers on that? I have bought a USB to UART connector, but don’t understand to what pins I have to connect everything.

Hi Martijn,

I found some documentation on the esphome page esphome.io. My boards are similar to this one: ESP-12F_Relay_X8 | devices.esphome.io

I have soldered wires and connectors onto my boards to ensure that I have easy access in an emergency situation and don’t have to search through the internet to find the right pin numbers.

I suggest that you practice a little bit with the wiring since I would assume some variations in the boards available on aliexpress.

BR David

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Thanks for the assist. In hind side it was pretty terrible. The wires just didn’t make a good contact. After reconnecting them with a “better” wire in between, I could program it without issues. Now to find the correct GPIO’s


Anyone any thoughts on how to work out how to get the correct GPIO connected to the relays? I now have an extremely basic config:

switch:
  - platform: gpio
    pin: GPIO16
    name: Relay1
    id: relay1

Copied from ESP-12F_Relay_X8 | devices.esphome.io, but it doesn’t do anything. Except when I switch relay 8, they all turn off. At least, I think they do. Because when the light is on at the relay, is the relay then turned ON or OFF?

– right, that is solved. When the relay lights are ON the relay is OFF. Now only to figure out somehow on which GPIO everything is connected

– right, found it. Works now , thanks. Apparently I have a shift registrar. At Generate Relay Config For ESPHome per https://www.gpmidi.net/node/163 · GitHub I borrowed a config which makes everything come up and running.

Have you ever figured out which settings are working for you? I mean the KP, KI, KD , KE? I’m finding it hard to fully understand what they are doing, even after reading a lot of explainations.

I don’t think I have been near those settings?
Where did you find them?

Hi,
I would like to know which thermoelectric actuators you use? I believe generally speaking you can choose between “smart TRV’s” which typically contain a temperature sensor and some logic to open/close the valve based on the requested temperature or a “dumb” thermoelectric actuator.

Since my valves are centralized and hidden behind a cabinet (like most people with underfloor heating), I’m more inclined to go for a “dumb” thermoelectric actuator that just opens/closes the valve based on a command (0-10V). But that is just theory. For the people that are using this in practice: which thermoelectric actuators do you use? Do you use some open/close actuators (NO/NC)? Or what about actuators that can partially open a valve? I have some rooms with pretty stable temperatures, so in that case a valve could be open for e.g. 20% for most of the time.

Hi Dries

I have the dumb actuators. They are a combination of Pettinaroli and Roth but all are dumb and NC. They work as binary, nothing with 20% or so.

BR David

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It is an integration I’m trying to use. See: GitHub - ScratMan/HASmartThermostat: Smart Thermostat with PID controller for HomeAssistant

Now first I have to find some spare time to hook everything up.

I’m still reading and learning before buying the hardware. I notice some buy 230VAC and other work with 24V. What considerations did you make before selecting 230/24V? I need to buy both my control board (ESP-based?) and my thermoelectric valves.

I didn’t choose cause I already had the 230VAC actuators.
And my control board is esp based.

Thanks. I was just wondering if there are any pros/cons when choosing 24V of 230V. I do have a 230V power socket nearby, but I can imagine most of us have 230V nearby and choose to transform it to 24V for some reason.

For me it is the same reason as @c957031 . I already have 10 actuators installed on 24v. So bought a 24v esp module.