No cold feet this winter – More Power To Your Underfloor Heating

It is a typical thought that comes back every summer. If you need to ‘repair the roof’, you had better do it while the sun shines. Not everyone is pleased with this conclusion –  some people enjoy relaxing in the garden during the summer months!

What goes for the roof also applies for the heating of your house. If you want to avoid cold feet this winter, you can start installing underfloor heating now. There are many ways to do this ‘summer job’: the first one is tempting, have it done by a professional plumber and ‘control’ the project from your sun-lounger in the garden! The other option requires some more action and separates the real DIY-er from the wannabees!

The work can be divided into placing the pipes, doing the plumbing and fitting a regulator so that you can control when the floor heating is working.

A MIAC industrial controller proves to be an excellent tool for the regulator part of the project. There are temperatures to be measured and valves that need to be switched. This is where the MIAC industrial controller comes in. The MIAC has all the inputs, relay switches and power drivers built in to control these processes. There is even a display for temperature reading and using the available function keys is a simple way to adjust settings manually.

Note: a project like this requires working with mains electricity, make sure you have the required knowledge and experience to work with this. Always call in the help of a professional when required.


The MIAC is an industrial grade control unit similar to a PLC (programmable logic controller), but more feature-packed and easier to program without having to resort to using the PLC specific ‘ladder logic’. To show off the capabilities of the MIAC and how you can replicate an expensive underfloor heating system for a house at a fraction of the cost, the diagram below shows how this could be implemented.

The heating system consists of a few major key elements.

  • Boiler
  • Electronic valves
  • Thermostatic mixing valve
  • Central heating pump
  • Air release valve
  • PEX under floor piping – Bought online from an underfloor specialist
  • Mains residual current detector (RCD) – to prevent the risk of electrocution
  • Temperature sensors, Thermistors
  • A MIAC (
  • Compression fittings to assemble manifold
  • Optional to communicate with the MIAC PIC, dsPIC or Arduino versions: Flowcode ( See screenshot below.

A lot of the items above can be found in high street DIY shops but if you look on eBay or Amazon then you can find some very good deals, which may save you a huge amount of money.


The MIAC is programmed to use a ‘look up’ table technique to read the value of the thermistor T2, which is situated in the floor near the PEX heating loops. The ‘look up’ table data is based on an Excel spreadsheet with values matching those of the thermistors. When the thermistor temperature drops below a threshold value we check to see if the loop is enabled and then we open the valves connected to the loop. We then switch on the pump and the boiler. As the boiler output water starts to heat up the thermostatic mixing valve does its work and starts to mix the cold from the output of the PEX loops with the hot from the boiler. We can monitor the temperature of the water running through the PEX loops by reading the thermistor T1. When this temperature is ok we shut off the boiler and the pump. Every so often we can activate the pump for a short time, to circulate the water and ensure that it is still up to temperature.


The MIAC can be programmed for this with Flowcode (assuming you opt for the PIC, dsPIC or Arduino version of the controller). Flowcode is a graphical programming tool that allows you to control your own electronics. If you are new to Flowcode, you can test and try a free version from the Matrix website ( Alternatively, the nature of the processors inside our MIAC controllers means you can actually program these using any programming language that supports such devices – including the Arduino IDE, MPLAB or even Python for the Raspberry Pi versions of the controller.


Please note that all electrical work will need to be inspected by a qualified electrician. Electrical regulations may differ from country to country, so make sure you check your local legal requirements.  If you decide to do similar things using mains voltages or plumbing systems then please ensure you get help and advice from qualified professionals in your area before you begin and again before you switch on or commission the system. Matrix TSL will be in no way held responsible.


The under floor heating is a nice example of what you can do with a MIAC. There are many other projects you can do. Check for more ideas and information on the full range of MIAC controllers.


You can order a MIAC directly at Now with 30% discount for a limited time only!

n.b. discount applies to dsPIC, Arduino and Raspberry Pi MIACs only.

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