Heating control & regulation
Common
We built a comfortable, flexible and cheap heating control. It is made for installing it in old heating systems.
With this control the boiler temperature is regulated depending on the outside temperature:
Low outside temperature --> High boiler temperature
High outside temperature --> Low boiler temperature
We realized a simple system with low amount of parts..
Beside a AVR-Ctrl-PCB only 2 Relays, 2 Temperature sensors (KTY81-110) + Resistors and some Switches / Keys / LEDs are necessary
A forum Thread (German Forum) (here).
What is possible with this control ?
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What has to be changed to the heating system ?
The insatllation is possible with minimum effort:
First we need the two temperature sensors.
One for the boiler temperature and one for the outside temperature.
This one sensor. Should be isolated afterwards.
This is the place, where I placed my sensor.
It is just touching the outgoing pipe of the boiler.
Now we need control obout the gas-ventile.
Let's take a look to the original system.:
There is a thermostat, which switches off the gas ventile when the boiler reaches the desired temperature.
We switch our relay contact (opener) in series of the original termostat.
Now our relais can control the gas-ventile.
Important: The old termostate is still operating. In case of failure of our heating control system, the original termostate will still switch off the ventile and regulate the boiler temperature!
The circulating pump can be switched of by th opener of our second relays. This saves energy costs, too.
Both relays use the opener-contacts. That means, if our control fails, the Relays switch off and the old operating mode is in use.
And with a simple switch it is possible to switch back to the old operation mode.
We placed the AVR-Control into this terminal-like case.
The blue keys are for the menu and the black to select the operating mode manually.
The LEDs show the state of the burner and the circulation pump.
Three LEDs (right side) show the current operating mode.
On the Bottom we see the "old operating mode" switch.
The control in praxis
This is my actual configuration.
Group 1 (Working)
Working day: Day from 6:30, Absent 8:00 - 16:30, Night from22:00
Sa, Su: Day from 8:30, Night from 22:30
Th: Absent 8:30 - 20:00
Fr: Absent 8:00 - 13:30
Group 2 (Holyday at home)
Working day: Day from 8:00, Night from 23:00
Sa, Su: Day from 8:30, Night from 23:00
Day, Absent:
Below 45°C boiler temperature the circulation pump stops.
How to setup the temperature courves?
Every operating mode (Day, Night, Absent) has its own temperature courve. Each courve is defined by two points:
max. boiler temperature at x°C Outside temperature &
min. boiler temperature at x°C Outside temperature
e.g.. 70°C boilertemperature ati -5°C outside &
30°C at 20°C outside temperature
These pointe are the edge-points for the regulation.
Each operating mode has also an own switching point for the circulation water pump.
To visualize the courves, we made a Windows-Program.
Here you can easyly see, which boiler temperature corresponds to wich outside-temperature.
Sources of the AVR-Software in Download-area.
The average outside-temperature and the gas consumption are stored in the EEPROM and can be displayed in the Windows-Tool.
Also a remote-control is possible via the windows tool.
Remote control via internet
If the windows tool is running on a PC, you can get access to this pc via a remote-display from the internet .
A connection to our Webserver-Project will follow...
Further ideas ?
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