Hello. I have a Panasonic AC, that I'm controlling via IR LED Diode (see schematics in repo), here is the actual picture of the AC: http://imgur.com/lXHxvWt. I'm also using similar heater: http://gazifikaciya-otoplenie.uslugi.catalog.bg/images/produ..., which I'm controlling via Servo (thermostat) and a central on/off relay. Going to add a video later tonight :)

In your pics I saw what looked like a servo turning your dial. Is that what you mean?

It's a great solution. Most houses in the US have central heating/cooling so the IR remote isn't an option. Although I have seen that style before.

What I want to do is integrate it directly with the system. Here's an example of a Honeywell connector similar to mine.

http://diyhousehelp.com/how-to/honeywell-4-and-5-wire-thermo...

https://youtu.be/wh0OoLUTeM8 Just added a video :)

Yes, that's what I meant. Unfortunately, I did not want to disassemble the unit as it would void the warranty.

I'm a bit confused here; looking at the video and pics of your water heater/boiler, the knob the servo is turning looks like it sets the temperature the boiler heats the water to for the central heating loop. This is generally not the thermostat, and once set to a value you are happy with shouldn't need to be adjusted.

Yes, it is not a thermostat, I have similar heater (also Vaillant) and it just sets the temperature of the water in the pipes (generally you set it higher when the outside temperature gets lower, and all the way up when it reaches the minimum at your location).

Is the relay for your heater controlling the main voltage input or is it controlling at the thermostat connection?

I've been wanting to do something similar with the units in my apartment (they're similar to what you'd see in a hotel window unit). The thermostat and controls are integrated and I can't disassemble to access them, so I either need to build a rig to push the buttons (hard) and turn the temperature dial or just put a relay at the mains and manually set them for AC\Heat depending on season. Adding a relay to the mains seems straightforward, but it's 220v and I don't want to mess up.

The relay is controlling the main voltage input and it's similar to http://i.ebayimg.com/00/s/NTAwWDUwMA==/z/ZS0AAOSwr81UNgc9/$_.... The relay's function is to act like a central switch. I have also a servo attached to the thermostat and it's only role is to spin the thermostat controller. The servo is similar to http://www.conrad.com/medias/global/ce/2000_2999/2000/2060/2...

You could also look at SSRs, which tend to be easily controllable with logic level outputs on a microcontroller.

Solid State Relays (SSR) do work great. Internally they use an LED to close the switch rather than the mechanical coil mechanism used in the classic click relays; these are totally silent.

I am using one to turn on/off the mains power of a 12VDC transformer. The nice thing about an SSR with an input range of 3–30V (a common type) is that you can drive it directly (and safely!) from a Raspberry Pi GPIO pin (3.3V).

Thanks! Will definitely look into them :)

Thanks!

How did you attach the servo? I have almost the same heater and was wondering if go with 7-8-9 or servo, but I haven't work with servos before, so do you have any pages that could help with those?

Wow, I'd never considered using a servo, but I might try it for automating the heating in my rented house where I can't change the thermostat itself, but could mount something above it to spin the dial.