Commercial Booster Pump Problems: Why Pressure Drops During Peak Demand

At 10:00 a.m., building water pressure seems fine.

At noon, multiple tenants are using water at once and suddenly the complaints begin. Fixtures are slow. Upper floors experience weak pressure. Water flow is inconsistent.

Commercial booster pump problems often become noticeable when building demand reaches its highest point.

It is easy to assume the booster pump itself is failing. Sometimes that is exactly what is happening. But pressure problems can also be caused by sensors, controls, piping, incoming water conditions or another pump in the system that is no longer responding properly.

That is why good troubleshooting looks beyond the pump.

What Causes Commercial Booster Pump Problems During Peak Demand?

Commercial booster systems are designed to increase water pressure when the incoming supply does not provide enough pressure to serve the building properly.

Depending on the application, the system may include multiple pumps, pressure sensors, pressure tanks, variable frequency drives and automated controls.

When water demand increases, the system should respond.

If it does not, one or more conditions may be limiting performance.

1. Incoming Water Pressure Has Changed

Start upstream.

What pressure is actually reaching the booster system?

If incoming pressure has dropped, the pumps may be starting with less available pressure than the system was originally designed around.

Comparing inlet and discharge pressure can help determine whether the problem begins before or after the booster pumps.

2. A Pressure Sensor Is Giving Incorrect Information

Automated booster systems rely on accurate pressure feedback.

The sensor tells the system when additional pressure is needed. If that sensor is damaged, restricted or inaccurate, the controls may not respond properly.

The pump can be mechanically capable of producing more pressure while the control system fails to tell it to do so.

3. Additional Pumps Are Not Starting

Many commercial booster systems use two or more pumps.

At low demand, one pump may handle the building easily. As water use increases, another pump may need to start.

If the second pump never enters operation, the lead pump may reach its limit.

This can create a very specific pattern: acceptable pressure during quiet periods followed by low pressure whenever building demand increases.

4. One Pump Has Been Taken Out of Service

A multi-pump system can continue operating even when one pump is unavailable.

That can hide a problem.

A pump may have:

• Tripped on overload

• Been switched to OFF

• Developed a VFD fault

• Lost electrical power

• Experienced a motor problem

• Been intentionally disabled during previous maintenance

At normal demand, nobody notices.

At peak demand, the remaining equipment cannot keep up.

5. There Is a Restriction Somewhere in the System

Valves, strainers and piping all affect flow.

A partially closed valve or restricted strainer may not create an obvious problem when flow is low. As demand rises, however, that restriction becomes much more significant.

Before increasing pressure settings or changing pump speeds, confirm that the water has a clear path through the system.

6. Building Demand Has Changed

Buildings evolve.

Tenants change. Renovations happen. Fixtures are added. Building occupancy increases. Operating schedules shift.

A booster system selected years ago may be serving a very different building today.

If equipment repeatedly operates at maximum capacity during ordinary building use, it may be worth comparing current demand with the conditions the system was originally designed to handle.

What Should Facility Teams Record?

When commercial booster pump problems occur, write down what is happening instead of relying on memory.

Useful information includes inlet pressure, discharge pressure, which pumps are running, pump speed, pressure setpoint, active alarms and the time complaints occur.

Patterns can tell you a lot.

If pressure drops at roughly the same time every weekday, that is useful troubleshooting information.

Don't Automatically Increase the Pressure Setpoint

Turning the pressure up can be tempting.

It may even appear to solve the problem temporarily.

But increasing the setpoint does not explain why the original pressure could no longer be maintained.

The change may simply make the pumps work harder while leaving the actual issue unresolved.

Look at the Complete Booster System

Commercial booster pump problems are rarely solved by guessing.

Incoming water conditions, sensors, pump sequencing, controls, valves, piping and building demand all affect the pressure available to occupants.

Academy Pump & Motor provides commercial pump sales, service, troubleshooting and repair throughout Calgary and surrounding areas.

If your building is experiencing inconsistent water pressure or your booster system cannot keep up during peak demand, Academy Pump & Motor can help identify what is happening.

Call Academy Pump & Motor at 403-437-7888 or visit academypump.ca.