Considerations

• Problems are more easily identified when it is determined if the radiant system is old or new. In an old system, a low-return water temperature in a loop is usually caused by a blocked tube. This indicates rust or sediment, according to the Radiant Design Institute.
  
  

Significance

• In a newly installed radiant heating system, a low-return water temperature usually indicates dirt or a pebble in the system. However, the most common problem, in a newly installed radiant heating system, is tubing that is kinked when concrete is poured.
  
  

Prevention/Solution

• Tubing failures are rare, according to the Radiant Design Institute. Problems are usually caused by damage during installation. Later damage can be caused by a screw or a nail; it is best, therefore, to prevent this by installing tubing in the bottom of the slab.