What Should You Know About Your Home's Circulator Pumps?

Posted on: 21 March 2022

If you have a hydronic heating system in your home, you might find the numerous pipes and associated hardware somewhat overwhelming. While some hydronic systems are relatively straightforward, others may involve many zones and extra equipment, such as vent dampers and expansion tanks.

You'll always have one or more circulator pumps among these many items. Depending on the design of your system, you may have one pump for each zone in your home. Alternately, your home may use a single pump and rely on mixing valves to control the flow to individual zones. Whatever the case, understanding your circulator pumps can help you maintain and prolong the life of your system.

Why Do You Need Circulator Pumps?

The typical residential boiler is a low-pressure system. In other words, the boiler heats water but keeps its temperature below the boiling point. As a result, the water in your system won't have sufficient pressure to move through your house on its own. Instead, you need a pump to continually push hot water to radiators, baseboards, and other heating devices.

The number of circulator pumps in your home will depend on the system's original design. If you have multiple pumps, the thermostat in each zone will turn the individual pump for that loop on or off. The main pump will run for single pump systems whenever any thermostat calls for heat. You may also have a secondary circulator pump that supplies water to an indirect water heater.

Do Circulator Pumps Require Maintenance?

Circulator pump designs vary. Sealed pumps are maintenance-free, although there's also typically no way to repair these units if they fail. Other pumps may have ports for adding oil, and these circulators require periodic maintenance. It's best to leave this maintenance task to a professional if you aren't sure how to check and add lubrication to your circulator pumps.

Like most mechanical pumps, your circulator pumps use internal bearings that can wear out or fail over time. Maintaining your pump (if possible) is the best way to ensure these bearings last for many years. Make sure you understand the type of pumps in your system so you know if yours require you to add more oil periodically.

What Happens When a Pump Fails?

Problems with circulator pumps are usually fairly easy to spot. If you have one pump per zone, you might notice it becoming colder in that zone. You can feel the pipes after the pump to determine if there's any hot water flowing into them. For a whole-house pump, you may notice your heat is no longer working, or it may simply take much longer for your home to heat up.

Depending on the model of your pump, you may be able to remove the housing to force the impeller to turn. However, if you aren't comfortable with this level of disassembly, or if you do not have a user-serviceable pump, it's best to contact an HVAC professional to evaluate your system and replace the pump if necessary.

Contact an HVAC contractor near you to learn more about this and other heating systems