Standard Control - Combimix - operating instructions

Underfloor heating requires a different approach to control compared to conventional heating systems.

There are three main elements of control for your Begetube underfloor heating system:

1. Individual Room Stat control.
   
   
2. Programmable Clock Stat for Night Setback control.
   
   
3. Combimix for Water Temperature Control.
   
   

Room Stats: Set all your room stats to your required comfort temperature (typically 16°C - 22°C).  Once you are happy with your setting do not make further adjustments.  The room stats directly control the actuators on the manifold, opening or closing the appropriate group(s).  As you do not need to have your house at full working temperature 24 hours a day.

We also utilise a Programmable Clock Stat for Night Setback Control: This Unit gives you the ability to set overall time temperature control with two different temperature settings.  When you want your house to be at the room stat settings you time the clockstat to call for the higher temperature setting which you set artificially high (typically 26°C, as the rooms will only get as warm as the individual room stat settings).  When you want your house to be at the night setback temperature you time the clock stat to call for the lower temperature setting (typically 16°C).  Setting the clockstat to the night setback temperature will turn the boiler and pumps off until the temperature drops to 16°C at the clockstat.  The temperature will only drop to 16°C if you have a lot of heat loss from your building (i.e. a very cold night).  By having this setback control, it stops the house cooling right down during the night so it is not then struggling to bring the house up to a working temperature in the morning.  To set the time and temperatures on the clockstat refer to the user instructions for the clockstat.  If you want your house up to temperature by 08:00 set the clockstat to the higher temperature setting at 06:00.  If you retire to bed at 23:00 you can set the clockstat to the lower temperature setting at 21:00.  There is approximately a two hour lead time and a two hour lag out time.

Combimix for Water Temperature Control: This unit is attached to the manifold and its purpose is to blend down the high temperature water from your boiler to a lower temperature suitable for underfloor heating. 

The maximum temperature setting on the thermostatic head of the Combimix is dependant on the floor construction:

• Timber Joist Floors have a maximum flow temperature of 60°C.
  
  
• Concrete Floors have a maximum flow temperature of 55°C.
  
  
• For most of the heating season these temperatures can be reduced by up to 20°C depending on the outside air temperature.  This will aid overall comfort levels and increase the economy of your floor heating system.
  
  
• Thus typical settings are:.
  
  
• Going into heating season set mixer to 30°C - 40°C.
  
  
• During the coldest spell set mixer to maximum for floor construction.
  
  
• Coming out of heating season set mixer to 30°C - 40°C.
  
  
• One of the main points to remember when controlling your system is that switching your system on and off several times a day is false economy.  Keeping your floor at a constant temperature is more economical and will give you better comfort level.