Steam Return Lines: The Secret to Increasing Your Boiler’s Lifespan

If you own an older building in New York City, especially a larger rental property, you likely have steam heat. Steam boilers and radiators became the norm in the city around the turn of the last century, and they are still an efficient form of warmth, albeit with a few modern tweaks. Modern-day steam return lines are an improvement on old-fashioned systems. When used properly, they can significantly increase the lifespan of your boiler. Let’s take a look at how steam return systems function, how they save your boiler, and what you can do to ensure your return lines are functioning properly for optimum boiler performance.

How the Steam Return System Works

An efficient closed system

Steam return lines are part of a closed system that includes your boiler, the radiators the boiler serves, and your heating pipes. You recall that in order to make the steam that supplies heat to your radiators, water is heated in your boiler until it reaches the boiling point. At that time, water changes phase from a liquid to a gas.

You can observe this physical phenomenon any time you boil water for tea or pasta. Some of the water will change into steam once it hits the boiling point, which is at roughly 212 degrees Fahrenheit, depending on the colligative properties of any chemicals (like salt or other minerals) in the water that may slightly elevate the boiling point.

Once the steam has released heat energy into the various radiators to which it is delivered, it can’t remain steam any longer. It cools and changes phase again, condensing and reverting to its original liquid form from a gas.

The problem with this condensation is that if the water is still in your radiator or nearby pipes, it will “fight” with any steam in the same space, causing water hammer, that annoying clanging that tenants hate so much. This isn’t good for your radiators or for your heat system pipes either, as it causes undue stress on them.

Also, you want the now-liquid water to be sent back to your boiler so it can be reheated and used again. Steam return lines allow this to happen. Often a steam condensate pump is used to assist with the return, where gravity or pipe anatomy don’t facilitate this happening on its own.

Why Steam Return Lines Save Your Boiler

Reducing wear and tear and saving on energy costs

Steam return lines aren’t just ideal for reducing unwanted noise and prolonging the life of your radiators. They also protect your boiler in several ways, which incidentally saves you money in the process.

If you think about the entire operation of your boiler during a few heat cycles, this makes sense. First of all, if water weren’t returned to your boiler tank in its liquid form, you’d constantly be feeding the boiler new water. Not only does this activate your automatic water feeder more often, but it causes the boiler to fire more as well. Whenever your boiler is turning on, you are both using more gas (an added expense) and putting wear and tear on the boiler.

Furthermore, steam condensate isn’t completely cold water like the fresh water being fed into your boiler when the tank becomes low. It actually retains a sizable percentage of its original energy in the form of heat. It takes less fuel to reheat water from a steam condensate line than to heat cold water coming from your boiler feeder. This energy savings can be quantified in the form of BTUs.

Again, this saves on fuel costs and boiler wear, which reduces your expenses in the long run. You might save even more money if you chemically treat your water before it enters the boiler. You typically won’t have to do this with water returned through your steam return lines, as it has already been treated.

Common Problems We See with Return Lines

Causes of boiler system malfunction

Steam return lines are only as good as their meticulous maintenance. Without taking care of them, your heat system will not function efficiently, and it could even affect the health of your boiler. The issues we see most frequently with steam return lines for our Calray Boilers clients include:

• Corroded pipes that need flushing or replacement
• Leaks in the return pipes (can be caused by corrosion)
• Return lines clogged with mineral scale or sediment (require flushing and possibly a filter further upstream in the system)
• Improper water treatment or water treated to wrong pH
• No flush valve to assist with cleaning
• Improperly piped return configuration
• Using an old wet return system without a condensate pump
• Leaks in the condensate reservoir
• Other boiler problems that affect the condensate return system (boiler feeder malfunction, for instance)

If you use a steam condensate pump, you may have problems with the pump itself. These can include:

• Dirty water in the boiler tank that clogs pump parts and degrades seals, gaskets, and valves
• Pump strainer not cleaned often enough
• Acidic water that corrodes the pump seals or other components
• Cavitation that occurs when condensate is too hot and creates a pressure differential between the pump and the outside environment
• Boiler pressure set too high for the pump
• Check valve causes water to flow in the wrong direction from the condensate receiver
• Condensate pump float rod stuck or not functioning properly
• Electrical issues with the pump, including overheating of the boiler room
• Pump discharging into a Hartford loop
• Plugged vent line that prevents air from escaping the system as it should

Boiler Maintenance Before Heat Season Begins

Autumn approaching fast

In the heat and humidity of New York summers, it can be easy to forget about your boiler system. However, fall is approaching faster than most property owners realize, particularly when it comes to maintenance of their heating apparatus. You don’t want to wait until a blast of cold weather sweeps in to remember that your boiler needs work to get it up and running properly.

Schedule your boiler check, including a look at your steam return lines, today so you can arrange a service call at your leisure and get your pick of appointment times. You will enjoy the peace of mind that comes with knowing your boiler system is in great working order whenever heat season arrives. Call Calray Boilers at 212-722-5506 or use our easy online form to set up your maintenance check now.