A service that we offer is the testing of steam traps with a thermal imaging camera. If the steam trap of your radiator fails open you will not be aware that it has failed since that radiator will still heat. However it will add to your fuel bill since any steam that was produced, and condenses any where other than in the radiator was just a waste of money to produce it. If enough steam is allowed to enter the return piping through a failed open trap, hammering noise may be produced and if more enters it may actually equalize the pressure in the return pipe and stop all steam movement entirely. This again will lead to higher fuel bills. Steam traps must periodically be tested to ensure they are still closing properly. It is a moving part and will fail in either an open or closed position. These are some of the most neglected components of a steam system yet they work themselves to death every time the system operates. With a thermal image it is quite apparent if the outlet of the radiator trap is the same temperature or near the same temperature as the traps inlet. That would be a bad trap.The trap pictured at the top left is a bad trap. The trap at the bottom left is a good trap. You can plainly see how the outlet of the trap is over twenty degrees cooler than its inlet which would be normal.