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Heat System Circulating Pumps: Check Yours Before Winter Weather Begins

By the time you read this, the snow may already be flying in New York City. If you are a property owner or manager, you probably have a lot on your hands making sure the boiler and heating system are up to the job of keeping building occupants warm. Your heat system circulating pumps are a key component when it comes to winter comfort. Here’s an overview of their role and how you can tell when a pump might be failing.

What Do Heat System Circulating Pumps Do?

Hot water distribution to radiators

Heat system circulating pumps perform a simple but essential service: they push hot water through distribution channels to take it from the boiler to radiators or baseboards for heat. In some cases, these pumps may also supply under-floor radiant heating elements or towel warmers.

Circulator pumps are centrifugal pumps powered by an electric induction motor, usually mounted near the boiler. In larger properties, there are rows of multiple pumps, each supplying different zones of the building or different units. These are sometimes referred to as “zone circulators.” You may also have one large pump with individual zone flow control valves that perform the same function as numerous smaller pumps.

What Are Some Signs of Heat System Circulating Pump Problems?

Warnings to heed

If you notice any of these signs with your heat system circulating pumps, it’s time to call the pros, as these indicate a problem that could lead to complete pump failure:

• Pump running only intermittently
• Pump won’t stop running
• Water leaking from the pump
• Pump casing uncomfortably hot to the touch
• Pump triggering circuit breaker
• Loud or unusual noise emanating from the pump
• Radiators not heating sufficiently
• Too much heat coming from radiators
• Pump showing signs of corrosion or mineral scale buildup

Why Do Circulator Pumps Function Poorly or Fail?

Too few pumps or pumps too small

Sometimes, not enough heat may be due to an inadequate number of pumps to handle the size of the building. Likewise, the pumps installed may not be the right size for the force needed to reach upper stories. In this case, adding more pumps or swapping out smaller pumps for more sizable ones can fix the issue. You may need to add circulator pumps in a series for taller buildings.

Improper mounting or installation

Noisy or vibrating pumps are often due to problems with mounting. It may be that the pumps were mounted incorrectly to begin with, or it could be that mounting fixtures have come loose over time and need to be tightened. Occasionally, we see pumps that were not installed properly, either by DIYers or inexperienced tradespeople. Another cause for excess noise is the need for new bearings or pump lubrication.

Pump old and at the end of its useful life

Every pump has a limited lifespan, although when well cared for, your circulator pumps should last a couple of decades or more. We can assess your pump and see if it is worth saving or if it needs to be replaced. Sometimes, replacing parts or putting in a new motor can extend its life.

Leaky connections or seals

Over time, connections and seals in and around the pump can come loose, crack, or harden, meaning water leaks out. This is messy, hazardous, and a waste of water and fuel. In this instance, connections need to be tightened, or defective seals need to be replaced.

Motor not working

If your pump motor is not functioning as it should, you’ll see a few possible symptoms. It may be that the pump doesn’t turn on at all or only works some of the time. Consequently, no heat is reaching the radiators served by the pump. This could be due to a bad motor or to electrical issues (see below).

Switch malfunction or poor electrical connection

Pump switches can fail, causing the pump not to turn on, to only turn on intermittently (often randomly), or to run constantly when it should shut off periodically. This can be due to a bad switch that needs replacing or electrical wiring that has become worn or loose. You may also notice your pump triggering your circuit breaker if you have electrical problems. It’s worth checking here to make sure your boiler thermostat is working too, as this can cause your pump to run continually.

Damaged pump impeller

The impeller is an interior part of the pump resembling a fan. Its job is to move water from the inlet of the pump to the outlet. If the impeller is damaged, it cannot do this, often because the damage reduces the amount of centrifugal force the pump can generate. In this case, the impeller must be repaired or replaced.

Mineral scale buildup

New York City is notorious for its hard water. This can lead to mineral scale accumulation (aka “lime”) in your circulator pump. Be suspicious of this if you have hard water buildup in other plumbing or boiler systems. Cleaning or replacing encrusted parts is a must, and installing a filtration system and/or treating boiler water will prevent this problem in the future.

There can be a few other reasons why your heat system circulating pumps aren’t working correctly, but these are the most common ones we see around the city on our service calls.

What Should You Do About a Malfunctioning Circulator Pump?

Call Antler Pumps

Heat system circulating pumps are devices that can rarely be fixed on your own. A pump specialist like Antler Pumps has the knowledge, experience, and equipment to get your circulator pumps back to optimal function quickly and reliably.

If you notice any of the problem signs listed above, or if you have other issues with your heat system circulating pumps, give us a call at 212-534-2500. Or you can schedule a service call with ease using our online form. Don’t wait until the cold weather hits to get your pumps fixed! Reach out now, and you and your tenants will enjoy the indoor comfort you need.