Welcome to the Cana-Vac central vacuum troubleshooting guide. Select an answer below to help diagnose your central vacuum system.


Does Air come out of the motor exhaust when all the inlet valves are closed and the system is sealed?
Start by checking suction directly at the central vacuum unit. This will tell you if the loss of suction is due to a problem with your vacuum or elsewhere in your piping system or accessories.
Try plugging your hose into the utility valve directly beside the power unit (if installed) and turn the unit on. Is there suction at the end of the hose? If yes then you know two things, (1) Your hose is not clogged and (2) there is a clog somewhere between your vacuum and the vacuum valves.


Possible Cause: Puncture in piping or disconnected piping
If you have determined that you have suction at the unit then there no reason you should not have suction at all valves. If this is the case and you don’t have a blockage it could be as simple as a disconnected pipe. If the system was installed without the pipe being PVC cemented it could be a pipe has become disconnected or that the piping has been punctured by a nail or dry wall screw.
Can you hear a hissing sound emitting from any part of the tubing system?
Connect the tubing system to the power unit. Close all the inlet valves so the system is sealed. Turn on the power unit and trace the tubing system back to each inlet. Listen for a hissing sound.
Possible cause: The system may have a leak
Determine where the hissing sound is coming from and repair the leak.
Possible reasons for leak:
- Faulty Inlet valve gaskets or valves
- Dry wall nail or screw has punctured tubing
- Tubing and or fittings not glued
- Tubing has cracked
Possible Cause: Piping system needs replacement
The hole creating the leak is either too large to make a hissing sound or the hissing sound is too muffled to hear it. In this case check all inlet valves and exposed tubing.
If inlet valves are fine, and no other solution is found. Then it is likely that the piping system needs replacement.

You may have a plugged filter. With the unit turned on, does the utility valve beside the unit have high air flow or low air flow?
Filter could be blocked. Try cleaning filter (DO NOT REMOVE). Your filter is designed to be maintenance free, however if vacuumed materials such as drywall dust have plugged the filter, simply wrap a garbage bag around the unit and reach inside with the bag and shake the filter. Wait a minute with the bag still snug around the canister to let the dust inside the garbage bag. Also try vacuuming the filter with a shop utility vacuum.

Plug hose into utility valve and turn on unit. Does the hose have good air flow?

Turn the power unit on and suck a small numbered piece of paper towel through each valve. Leave valve door open enough to suck each piece of paper to unit. Did all numbered pieces make it back to the unit?
If not all the pieces made it back into the unit, it could be a clogged hose.
Solution: Turn unit “off”, take the hose out of the inlet and reverse the hose so that the vacuum nozzle wand is in the inlet valve and turn the unit “on” using the on/off switch on the side of your Cana-Vac central vacuum (Diagram – Item 3). This should remove the clog.
Check the power unit sealed vacuum level with a vacuum gauge.Is the vacuum level good?
If the level is good, make sure the power of the unit is suitable for the size of the home and the number of inlets installed.
If the level is NOT good
Make sure the voltage at the receptacle were the power unit is plugged in. Is the proper voltage being supplied to the power unit. If the proper voltage is being supplied: The motor may be bad. Repairs or a replacement may be needed.
If the proper voltage is not being supplied: Call an electrician to look into the voltage problem.

Possible Cause: The host has a clog.
Solution: Turn unit “off”, take the hose out of the inlet and reverse the hose so that the vacuum nozzle wand is in the inlet valve and turn the unit “on” using the on/off switch on the side of your Cana-Vac central vacuum (Diagram – Item 3). This should remove the clog.

Please disconnect low voltage wiring and make sure power unit is plugged in. Does the unit still run with the manual switch “Off”?

Possible Cause: The control module may need to be replaced
Check the vacuum unit and insure that the override switch is in the “off” position. (Diagram – Item 3)
Are all vacuum hoses out of all wall inlets? Remove.
Disconnect the low voltage wire (Diagram – Item 2), if the unit still will not shut off then there is a problem with the relay control board which must be serviced.

Is the green light on?

Short the low voltage connector by bridging the low voltage connection. Does the unit turn on and off?

Connect low voltage wires back to unit. Does the unit turn on?

Possible Cause: There may be a Low voltage wiring problem
Remove all vacuum hoses out of all wall inlets. If the unit still will not turn off There may be a short somewhere in the low voltage system which is causing the system to short.

Do all the inlet valves work?
Your electrical system appears to be fine
We apologize we were unable to solve the issue.
Please start over with a different symptom or contact us for assistance.
Possible Cause: There may be a low voltage wiring problem
Remove all vacuum hoses out of all wall inlets.
If the unit still will not turn off There may be a short somewhere in the low voltage system which is causing the system to short.

Possible Cause: The control module may need to be replaced
Check the vacuum unit and insure that the override switch is in the “off” position.
Are all vacuum hoses out of all wall inlets? Remove.
Disconnect the low voltage wire (Diagram – Item 2), if the unit still will not shut off then there is a problem with the relay control board which must be serviced.

Possible Cause: The control module may need to be replaced
Check the vacuum unit and insure that the override switch is in the “off” position.
Are all vacuum hoses out of all wall inlets? Remove.
Disconnect the low voltage wire, if the unit still will not shut off then there is a problem with the relay control board which must be serviced.

Please disconnect low voltage wiring and make sure power unit is plugged in. Does the unit still run with the manual switch “On”?
Please check to see if the control module and motor are wired correctly. If they are not wired correctly, connect the wires.

Try the appliance in another electrical outlet. Does it work?
If it does not work: The motor may be bad and may need a replacement or repairs.
Please contact a local dealer
If it does work: Please call an electrician to fix the bad outlet.