Steam Trap Testing & Troubleshooting Guide

Steam Trap Troubleshooting

Steam trap troubleshooting is a necessary step in diagnosing problems that will arise at some point in the life cycle of your steam system. Therefore, it’s important to schedule routine testing of your steam traps. Steam trap failure is caused by improper removal of the condensate. When the steam trap shows signs it can no longer remove condensate from the steam system efficiently, it’s a sign the traps are failing. Increased inefficiency means wasted fuel and an overall increase in production costs.

Even though different types of steam traps were developed over the years for different functions, essentially, a properly functioning trap differentiates between steam and condensate to allow your system to produce energy efficiently without compromise. However, steam traps are no different than any other mechanical device; eventually, parts wear out and the device malfunctions. Regularly scheduled maintenance should prolong or even extend the longevity of the steam trap and its parts. That said, keep in mind that a steam traps’ life expectancy is no longer than 3 years, and some steam systems have an annual steam trap failure rate of as high as 35%.

Causes of Steam Trap Failure

Factors that cause steam traps to fail or accelerate failure vary, but here are a few of the most common:

  • Feed water contamination can pose problems
  • Quality of feed water plays an important part in the life of steam systems
  • Dissolved gases like carbon dioxide can turn the condensate acidic and cause corrosion of steam traps
  • Improper steam trap sizing for the given application (If undersized, steam traps are inclined to fail faster compared to correctly sized steam traps)
  • Prevent entrainment is another important factor. It’s good practice to install a strainer before or ‘upstream’ of every steam trap. Even though some steam traps have built-in strainers, a separate strainer ensures there will be no rust entrainment or other debris inside the trap.

All steam traps need proper maintenance. Establish a maintenance calendar and adhere to it. Regularly scheduled maintenance can identify and anticipate problems. External visual inspections can reveal signs of corrosion and leakage. Whether the steam trap is functioning properly or not, observation is the first step in maintenance and troubleshooting. You may find other early signs such as a cold trap with no discharge, a hot trap discharging a torrent of steam, or sluggish heating, or noisy, banging, pounding pipes, all of which indicate a steam trap problem.

Steam Trap Troubleshooting

In general, when steam traps fail, it’s one of two ways—they’re closed or open. You’ll know you’re in trouble when

  • That once slow rising plume of steam out of the condensate stacks either starts to increase and jet out constantly and uncontrollably (stuck open)
  • Expelled steam sputters down to occasional wisps or nothing at all (stuck closed)

Cold Steam Trap (Stuck Closed)

A cold steam trap is a trap that’s not opening, and has failed closed. Condensate cannot discharge, and if condensate is not discharging, the steam system will not heat. It will back up in the trap and the transfer of latent heat will stop. A failed bellows assembly is more than likely the problem. A tell-tale sign is water hammer in the system, which can damage a bellows assembly.

Excess Steam Discharge (Stuck Open)

When a steam trap fails open, steam will blow through the trap and energy is wasted. With the valve open, hot steam discharges continually. More than likely dirt has accumulated on the valve seat or the trap bellows has failed. You can detect this by sound but, due to the trap being hot (it’s passing steam), it also means the system is not heating properly. You may have to replace the trap bellows assembly and definitely clean the trap. All that condensate previously heated up and treated will exit the system and have to be replaced with cold city water, and then heated and treated once again.

Steam Trap Maintenance

In sum, the best way to ensure longevity is to schedule routine inspections, keep steam traps clean, and be alert to troubleshoot. Dirty traps can cause plugging or leaking and lead to failure. It can also cause pressure surges, which could damage the steam traps and-or cause water-hammering throughout the system, wherein, your traps will wear out prematurely. For that reason, testing and troubleshooting are essential to maintain peak performance of your steam traps.


Arthur Harris has over 130 years of experience in manufacturing high-quality stainless float balls used in steam traps and other industrial applications. If you are in need of reliable floats, contact us today!

Arthur Harris Contact Bar

Leave a Reply

  • (will not be published)

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>