The reasons why PEX Expansion Fittings are not hot are as follows:
1
Air blockage in floor heating pipeline
Check whether there is air blockage in the pipeline, that is, the air in the pipeline does not flow and the water does not flow. At this time, the return valve should be closed, and then the exhaust valve on the return water should be opened. Each valve on the inlet water should be closed first, and then all the way to open the exhaust.
2
The heating period is over but not all the water is released
After the annual heating period is over, the user should discharge all the heating water in the floor heating pipe network. Otherwise, the long-term fouling will not be removed, which will cause the flow rate to be reduced, the water flow is not smooth, the heat transfer efficiency is reduced, and the pipe network is blocked.
3
Floor heating construction defects
The quality of the construction personnel is low, without professional training, rough construction, the pipeline appears dead bends, flattening phenomenon, resulting in poor water flow and increased resistance. The pipe spacing does not meet the design requirements.
4
Floor heating pipe has not been cleaned all year round
After the floor heating pipe is used, there will be biological slime, impurities, and bacteria. In addition, due to the temperature change of the water supply, calcium and magnesium ion scale will be attached to the inner wall of the pipe for a long time. If it is not cleaned and maintained in time, it will cause the floor heating pipe As the inner diameter gradually narrows, the water flow will become smaller and smaller, which directly affects the heating effect.
5
The return pipe valve does not open
I don't think I need to say more about this question. The inlet water is turned on, the return water is not turned on, the hot water cannot circulate, and it must not be hot.

Method

The solution to the floor heating return pipe is not hot:
1
Air blocking solution
There is air in the floor heating pipe, which causes air resistance. The solution is to open the air release valve to release air, and close it when water flows out.
2
Solutions for pipe network blockage
If it is because the filter is clogged with sediment or too much silt in the floor heating pipe, the water flow is slow, you can clean it yourself or find a floor heating cleaning company to clean it.
3
PEX Crimp Fitting backwater valve closed solution
Check whether the backwater valve is fully open or not (a "one" shape is open, and a "cross" shape is closed).