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Circulation Pump Problems

Circulation Pump Diagnostic Guide (Read Before Ordering)

The circulation pump is responsible for constantly moving water through the heater and filtration system. When a circulation pump fails, the spa may lose heat, show error codes, or stop filtering properly.

Common Symptoms of a Bad Circulation Pump

• Spa will not heat
• No water movement from circulation return
• Spa displays FLO, FL1, FL2, DR, DRY, or OH errors
• Pump is humming but not moving water
• Pump is completely silent
• Spa repeatedly trips heater errors

Step 1 – Verify Power to the Pump

Before replacing the pump, make sure the control system is actually sending power to the circulation pump.

• Turn power OFF to the spa
• Inspect pump wiring connections
• Restore power
• Use a voltmeter to verify voltage at the pump

Note: on 115 Pumps check voltage between the White and Black Wire for 115v. If it is a 230V pump check between the white and Black wire. On 230V systems the white wire is hot.

If there is no voltage at the pump, the problem may be the control board or wiring, not the pump.

Step 2 – Check for Pump Obstructions

Circulation pumps can sometimes become blocked by debris.

• Turn power OFF
• Remove the pump union
• Inspect the impeller area
• Look for debris or buildup

Note: If you ever remove the filters to clean them, power down first. If you don’t and there are any items floating in the tub they can be pulled into the front suction side of the pump. I have seen many things pulled into the pumps like bikini bottoms and more.

Debris in the impeller can stop the pump from moving water.

Step 3 – Listen for Pump Operation

• Humming sound – Pump motor is powered but the impeller may be stuck.
• No sound – Pump may not be receiving power or motor may be failed.
• Loud grinding noise – Pump bearings may be worn out.

Note: Air locks can only happen after refilling the tub they cannot just get air locks after being filled and used

Step 4 – Check for Air Lock

After draining and refilling a spa, circulation pumps sometimes become air locked.

• Loosen the pump union slightly
• Allow trapped air to escape
• Retighten the union

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This often restores water flow.

Step 5 – Verify Water Flow

A circulation pump may be running but still not moving enough water.

Check for:

• Dirty filters
• Closed slice valves
• Blocked plumbing
• Collapsed filter cartridges

Note: If you ever remove the filters to clean them, power down first. If you don’t and there are any items floating in the tub they can be pulled into the front suction side of the pump. I have seen many things pulled into the pumps like bikini bottoms, leaves and more.

Restricted water flow can cause heater and flow errors.

Common Circulation Pump Types

• Laing E5 / E10 circulation pumps (Low Flow No repair Parts only complete pumps)
• Balboa circulation pumps (There are repair parts for most models)
• Grundfos circulation pumps (Low Flow No repair Parts only complete pumps)
• Aqua-Flo circulation pumps (There are repair parts for most models)

Always verify:

• Voltage (115V or 230V)
• Union size (Typically 1 ½” or 2’ but there are some odd 1”)
• Plumbing orientation
• Connector type

Important Electrical Parts Policy

Electrical components cannot be returned once installed.

Please verify voltage and plumbing size before ordering.

Call for basic support or parts help or Text pictures for part identification. Call 1-866-829-3660 or Text Parts Pics to 772-800-5445. Know Before You Go.