My mat is not heating evenly. It is plugged in accurately. What is wrong?

The most frequent reason for controller fault is loss of signal between the mat connector and the controller plug (it should be connected with effort and really TIGHT) and error accumulation.

Sometimes the easiest way to solve the problem is to disconnect the controller's plug from the socket first and then from the mat connection terminal. 

When you disconnect the controller's plug from the mat connection terminal, please, always do it carefully with two hands. Hold the connector with one hand while the other hand pulls the plug. Pull the plug carefully out of the connector on the mat. 

Do not pull wires because the connection between the mat terminal and the controller plug may become loose.

Next, reconnect the controller to the mat tightly and then plug it into the electricity socket again. 

Reconnection and reset are the most common ways to eliminate errors and reload the controller. 

Here is the link to an article about how to check if the mat is heating well. It mainly refers to when low heating is detected, but it is also useful to understand how it works in general.

Low Heating FIR Mat Temperature Testing

In short, if some part of the mat has something on top of it (blanket, pillow, body…), this object will block some heat, and those parts of the mat will be hotter to touch.

You must cover the mat completely while preheating it.

If you cover the mat partially, the temperature sensors positioned in the different layers of the mat around all the surfaces will report different and controversial measurements to the main controller.

Finally, the controller may lose calibration and start to work incorrectly or malfunction.

So, please, always cover the mat completely while it is preheating to set level.

Put the mat on level 7, cover it with a blanket. In half an hour, in an hour, and 2 hours, remove the blanket for several seconds and immediately measure the temperature in several areas of the uncovered mat. 

Since the mats are handmade, there are some individual differences between the mats. Still, in general, the temperature difference between different areas with direct heating should not be more than 15-20 degrees F after 2 hours of pre-heating under a thick blanket.  

We use special sensors on the whole mat surface in the lab, but at home, a standard laser Infrared Thermometer can be used, such as this one for $14:

https://www.amazon.com/dp/B00837ZGRY

The end tubes with crystals and edges of the mat do not have direct heating due to safety reasons. They are heated indirectly by the heat coming from the adjacent stones, so it is OK for them to be less hot.

But if after 2 hours there is a big difference within the surface of the mat direct heating area, it may be a sign of some issue with the controller or temperature sensors calibration inside the mat.

We use heavy-duty ventilated controllers, but they still demand some care and should not be left on the hot mat to avoid overheating damage. Power spikes during hurricanes or blackouts can also damage controllers. It is always better to unplug the mat from the wall socket when you do not use it and connect it through a plug-in surge protection device when in use.

If the problem persists, it may be some form of a delayed factory defect, or such problems may also occur if the mat is mostly used partially (when you seat or lie only on the half of the mat so that the other part is not heated evenly). 

Other causes are the heating elements moving inside the mat and sensors malfunction, so it is important not to store the mat vertically along the wall and avoid extra pressure such as walking on the mat, bending, or folding it hot.

If factory defects really cause a problem, we will replace the controller or the whole mat.