Steam Condensate Pump Maintenance: Keep Your Heat System Running Smoothly

The summer is the perfect time to evaluate your building’s heat system and conduct maintenance before heat season starts. One of the most essential parts of your boiler and radiator system is your steam condensate pump. Here’s a review of the pump’s function and tips for condensate pump maintenance, which will not only save you a lot of headaches but extend the life of your boiler as well.

What Does the Steam Condensate Pump Do?

Recycling heated water

Many heat systems in New York City multi-residential dwellings are what we call closed systems. Water is heated in the boiler tank until it becomes steam (evaporation), which is the gas form of water. Then, it is sent to radiators in the building’s units to provide warmth for occupants.

After the steam has been in the radiator for a while, it loses energy as it gives off heat. Eventually, the steam turns back into liquid (condensate), which is returned to the boiler. The steam condensate pump assists with this task, as the pressure from the boiler isn’t sufficient on its own to draw the condensate.

The Importance of Your Steam Condensate Pump

Boiler system longevity and cost savings

Reusing condensate has multiple advantages. Rather than pumping fresh cold water into the boiler tank via the automatic boiler feeder, condensate can be reused. This saves on water consumption, plus it requires less boiler work because the condensate is already warm. It takes less energy to turn warm water into steam than it does to transform cold water into steam.

All of this efficiency translates to various cost savings. The boiler runs less, so there is less wear and tear, thereby extending its lifespan. Additionally, the boiler feeder doesn’t run as often, so that component is also less subject to wear and premature expiration. Finally, you save money on the water bill because you’re reusing the same water, not piping in fresh water from the municipal supply.

Condensate Pump Problems and Solutions

Dirty water

The steam condensate pump is set to pull condensate at a precise pressure. However, the pump may not be adequate if it has to overcome excess friction caused by dirty pipes and residue in the water, like rust, sediment, or mineral scale.

There are several ways to ensure the water in your heat system is clean. First, you should be treating your boiler water to the correct pH, which reduces corrosion of the tank and your plumbing system. It also prevents the buildup of unwanted material on the boiler’s interior tubes and in the steam return system.

Also, you can add a filtration system to the building, which can be helpful if your pipes are prone to accumulating sediment or hard water scale (usually a problem in Queens, which has a different water source than the other boroughs).

Clogged strainer

A strainer is another way to protect your steam condensate pump from dirty water. If your pump isn’t running properly, always check the strainer to see if it’s in need of cleaning. You should do this at the end of every heat season, but you may need to do it more often if your water is especially high in particulate matter. Signs that your strainer is causing condensate pump problems are the automatic feeder running more frequently than normal and water hammer in your pipes or radiators.

Boiler pressure too high

You always need to maintain a pressure gradient between the source of condensate (radiators) and the boiler collection area. If the boiler pressure is set too high, there won’t be a large enough pressure differential. You’ll know this is a possibility if too little condensate returns to the boiler, particularly if you’ve ruled out other troubles. Our partners at Calray Boilers can help you make boiler pressure adjustments to increase the gradient and entice more condensate to flow back to the boiler.

Pump cavitation

The pressure and temperature settings for your boiler and condensate return system are quite exacting. If the condensate is returning too hot to the boiler, usually due to there not being enough steam traps allowing it to cool slightly, it can cause cavitation. This is a type of pump failure when water flashes into vapor and becomes volatile inside the pump.

It can permanently damage the pump’s impeller, so it’s essential to prevent cavitation. Always make sure there are adequate, properly working steam traps in your system. Furthermore, use a controller with your condensate pump, which will detect any problems that could lead to cavitation and shut down the pump and/or alert you before damage is done.

Malfunctioning check valve

Check valves keep fluid flowing in the proper direction; in the case of your heat system, the check valve keeps boiler water from flowing into the condensate receiver. If the valve fails, it will activate your pump as if condensate is collecting. But if there is no real condensate to draw, the boiler feeder will also be activated.

If you find both pumps running too much, even simultaneously, your check valve may be the culprit. It should be cleaned, and it may need to be replaced if cleaning doesn’t solve the problem. You can assess your check valve by following these steps:

• Close the service valve located at the condensate pump inlet.
• Watch to see that water has stopped flowing into the pump’s receiver.
• If the pump keeps trying to cycle, it means water is coming from the boiler, not from radiators via the actual condensate return system.

Faulty float rod

Your condensate pump relies on a float switch to activate the motor. When liquid rises in the receiver, the pump turns on, and vice versa. If the float is broken or stuck, the pump won’t be triggered to operate. Sometimes the ball at the end of the float (similar to old-style toilet tanks) cracks and fills with water. Usually, this is a problem you can fix yourself by replacing the float or making sure it’s not sticking to the collection receptacle.

Issues common to all centrifugal pumps

Of course, there are problems that we see with all centrifugal pumps, which can also occur with a steam condensate pump, such as:

• Clogged or broken impeller
• Broken drive shaft
• Hardened, cracked, or leaking gasket or O-ring
• Worn bearings
• Need for lubrication
• Loose mounting
• Frayed or malfunctioning electrical elements (wires, plugs, etc.)

These are typically issues that need to be addressed by an expert, especially if they are associated with the pump’s internal components or its motor. We are happy to take a look and perform repairs on-site or at our shop, as needed.

We can also deal with less common steam condensate pump maintenance concerns like the need for a vacuum breaker, repositioning the master trap, a plugged vent line, or the pump erroneously discharging into a Hartford Loop.

Don’t wait until heat season has started to do the necessary upkeep on your condensate pump. Call Antler Pumps today at 212-534-2500 to schedule a service call while you still have the leisure of warm weather to address any problems.