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Common Problems with Pumps: Know Your Pump Anatomy to Look for Impending Pump Failure

The pumps in a New York City condo or co-op building keep many systems running smoothly, especially those related to the boiler and plumbing, as well as the disposal of waste. Knowing about basic centrifugal pump anatomy can help you identify common problems with pumps, so you can fix them before a pump fails completely.

While every pump is built with slight differences in its design, there are parts that are shared with all centrifugal pumps. Here are some things to look for that could indicate one of your pumps is going to go on the fritz soon. Catch these problems now, and you can save yourself a lot of time, headaches, and money.

Electrical Components

Power for the motor

Today’s pumps are almost always powered by electricity, which means these elements must be working properly for the pump to function as desired. If you observe any of the following, it could mean the electrical power for your pump isn’t working right. Be careful, as these problems can also cause shock to workers or issues with other items on the same circuit:

• Loose or broken switch – causes the pump to either run continuously, not turn on, or run intermittently, not always when it should
• Frayed, loose, or broken wires – can mean the pump isn’t getting adequate power and may trip circuit breakers or cause flickering lights; can also cause sparks or risk of fire
• Broken or melted plug – (for pumps that aren’t hardwired) must be replaced immediately, as this is a fire danger and may be caused by the pump or, more likely, by the outlet where the plug has been used

Pump Casing

Protection for the pump’s vital parts

The pump interior is protected by a casing, also sometimes called a housing or cover. The pump casing is particularly important if the pump is moving hot water or steam because it protects people working around the pump from burn injuries. Usually, thermal casing inside the outer housing adds more insulation.

Other parts related to the pump casing include:

• Inlet – where fluid enters the pump
• Outlet – also called the discharge end, where fluid exits the pump
• Mounting system – used to hold the pump in place, whether by straps, screws, plates, or other means

If you have a leak coming from the pump, it could be from a breach in the casing. If the housing is quite old or has been corroded by acidic water, it should be replaced. Otherwise, you risk damaging the pump’s internal components. It could also be due to a problem with a seal (see below).

Noisy pumps can be caused by multiple things. However, if the noise is also accompanied by excess vibration, your first suspect should be a loose mounting.

Seals

Prevention of leakage

Water and other types of centrifugal pumps use a variety of seals, gaskets, and O-rings to prevent liquid from leaking out. These are found throughout the pump structure anywhere protection is needed. If you notice a leak in your pump and have ruled out a problem with the casing, a seal problem is the likely culprit.

Pump seals should be replaced as soon as you notice they are cracked, hardened, or misshapen. This is a relatively inexpensive part that can save you having to replace the entire pump.

Valves

Directing the flow of liquid

Pump valves are parts that dictate which way liquid can flow in the mechanism, much in the same way valves in your heart and circulatory system determine the flow of blood. Valves are designed to keep liquid moving in one direction so it doesn’t flow backwards (upstream).

A broken, clogged, or dirty valve can be another cause of pump leaks. Bad valves can also result in lowered pressure from the outlet side or fluid backing up on the inlet side of a pump.

Just like worn seals should be replaced right away, so should old valves that have outlived their usefulness. If a valve is only lightly clogged with sediment or mineral scale, it can usually be cleaned with something acidic (vinegar or lemon juice) and returned to its place.

Impeller

Essential for moving fluid

The part that does all the work in a centrifugal pump is the impeller. This looks like a fan with blades that rotate and push liquid to its destination. There are many different structures for impellers, and often they are fully covered or covered on one side (shrouded).

A problem with your impeller will affect the entire pump operation, so it’s vital that impeller problems be addressed immediately. Common issues include:

• Clogged impellers – same as valves, above
• Mechanical issues with the shaft connecting the impeller to the motor
• Pitting – a sign of pump cavitation, the result of pressure imbalances that cause the liquid being pumped to turn into a vapor

Cavitation can be disastrous for a pump. If you notice pitting on your pump’s impeller, it’s best to alert your pump specialists. It could be the pump’s settings need to be adjusted; it’s also possible the pump size or inlet/outlet size are wrong for the demand being placed on it. A noisy or vibrating pump that’s not caused by a loose mounting part may be a sign of cavitation.

Lubrication

Necessary for smooth operation

Like the engine in your car, a pump needs lubrication to keep running without friction. Therefore, it’s equipped with a variety of lubrication mechanisms. As well as oiling the pump, you may need to clean or replace bearings regularly. If you’re not sure how to do this, Antler Pumps is happy to come out and do it for you, as part of our regular pump maintenance checklist.

How do you know if lubrication is an issue? You typically hear loud screeching noises or scraping sounds. The pump may also overheat and shut down.

Pump Sensors

Triggering the pump to turn on

Some pumps have sensors that tell them when to turn on. Three common pumps that use this mechanism are:

• Sewage ejector pumps (aka sewage grinder pumps)
• Sump pumps
• Boiler automatic water feeder pumps

If you have one of these pumps that is either not turning on when it should or that runs without stopping, it may well be the sensor is stuck. A thorough cleaning and check to make sure the sensor is able to move freely should fix the problem.

Do you have a pump problem that is out of your wheelhouse and needs professional attention? Don’t wait until your pump fails to take action. Call Antler Pumps today at 212-534-2500 to schedule an appointment.