Underfloor heating valves

Hardware Home Automation
1

My heating system contains underfloor heating circuits. Could you please recommend underfloor heating valves which can be operated via Openhab?
Thank you in advance for your help.

2

I think most people would tune each zone for balance, as each zone would be different length and then control the pump. Are you seeking to control each zone individually?

3

Hello,

IMHO you should buy normal valves (12V or 230V) and control them using z-wave or wired network (like http://www.aliexpress.com/item/8-Channel-Relay-Network-IP-Relay-Web-Relay-Dual-Control-Ethernet-RJ45-interface/32269500076.html with proper UI parser for managing this with URLs and OH). Then you will have to create proper rules which will open and close valves according to … something (you will have to know floor/room temperature or returning water temperature).

Regards

4

Zones which are in same room should work together, but others should work separately. Balancing is made manually, valves will only turn on or off each zones when heating is required.

5

Thank you for your answer.

  • Which controlling method (binding) would you recommend for a ethernet controlled relay? SainSmart also has ethernet controlled relay module.

  • Z-wave? How would you control manifold valves with z-wave? Could you please explain your idea more precisely?

6

underfloot heating valves have servomotors (I hope I’ve used correct word) attached on top of them and this servomotors can be NO or NC (open or closed by default - its up to you which you’ve choose). Using relays from ehernet relay gateway you can close/open valves using servomotors by contacting OH and ethernet relay gateway. Ethernet gateway must have some kind of URL API which will allow setting relay states using URL so you can use this URLs with http binding from OpenHab. Something like this one in item file:

Switch  Parter_Kotlownia_Pompka { http=">[ON:GET:http://IPADDRESS/relay.php?id1=state=1] >[OFF:GET:http://IPADDRESS/relay.php?id1=state=0]" }

Relay from Aliexpress does not have any URL API but this can be handled by simple PHP script (relay.php):

<?PHP
  $location="http://IPADDRESS/relay_en.cgi";   
  $ch = curl_init (); 
  curl_setopt($ch,CURLOPT_URL,$location); 
  curl_setopt($ch,CURLOPT_RETURNTRANSFER,1); 
  curl_setopt($ch,CURLOPT_USERPWD,"admin:12345678"); 
  curl_setopt($ch, CURLOPT_TIMEOUT, 10); //times out after 10s 
  curl_setopt($ch,CURLOPT_FOLLOWLOCATION,1); 
  curl_setopt($ch,CURLOPT_POSTFIELDS,"saida1off=off&saida3off=off"); 
  $result = curl_exec ($ch); 
  //print $result; 
  echo(substr($result,strpos($result,"saida3pluse")+99,3));
  curl_close($ch); 
?>

it is not finished but it sets output 1 and 3 to off:

  curl_setopt($ch,CURLOPT_POSTFIELDS,"saida1off=off&saida3off=off");

and then reads output 3 state:

  echo(substr($result,strpos($result,"saida3pluse")+99,3));

Regards

EDIT: When using z-wave you will have buy X number of relays or double relays to control each servomotor so it will be more expensive but easier to install (especially when you don’t have ethernet connection near valves)

7

SainSmart has an ethernet controll module with URL API. Thank you, it is a good idea.

1 Like
8

In the UK at least, most of these servo heating valves only require a single input, so a single zwave switch (or any other switch) can control a single value… When the switch is activated, the motor will drive the valve closed (or open - depending on what type you get) and when you turn it off, they have a spring that returns it to the other position.

Chris

9

This is exactly what I was talking about but having double relay z-wave device will let you control two servos :slight_smile: so it will be cheaper per controlled circuit.

10

Ah - ok, sorry. I thought that the servovalves you were looking at had separate open and closed inputs, so a single valve needed a double switch :smile:

This would certainly be reasonably simple and economical.

Chris

11

Dear Chris, I absolutely understand the logic. I need exact hardware (zwave relay, switch) recommendations because I didn’t find the right product on the Zwave homepage. Could you please recommend a switch what you mentioned?

12

If you are in Europe then I would recommend the Fibaro FGS221 which is a dual switch (or maybe the 222 is a newer version but it’s basically the same).

Other similar devices are available - I mention the Fibaro as I have them in my house for controlling lights and they have worked well for 4 years or so now.

Cheers
Chris

13

I have used my IHC installation to control the valves which have a “telestat” servo on top. These actuators usually have a really long open time (6 minutes is not uncommon). The benefit of this is that by using a pwm type controller or pulsing the signal at some frequency it is possible to control the heat input and make the floor heat much more constant.

This is in my system enabled by a temperature sensor that is embedded in the concrete floor such that I can use the actual floor temperature as the control input.

If you want to do this pulsing of the actuator (that gives a slowly moving valve) you need to think about outputter. If they are relays then they might wear out faster than some kind of solid state stuff.

I hope this helps you in some way