How to Finish a Basement Bathroom – sewage basin high water alarm installation and wiring. This project is continued from How to Finish a Basement Bathroom – Part 10. See the series introduction for the project index.
Basement Bathroom Sewage High Water Alarm
The purpose of a high water alarm is to alert you that something is wrong so you can stop using the basement bathroom before the sewage basin overflows. Possible causes of a high water alarm condition are:
- Sewage ejector pump is not working
- power outage
- circuit breaker has tripped
- pump is jammed or clogged, possibly due to a foreign object flushed down the toilet.
- Sewage pump is undersized – not enough horsepower.
- Check the manufacturer’s pump sizing curves which specify the Gallons per Minute versus Total Head (vertical height of water column).
- Sewage discharge pipe is clogged.
- Check valve malfunction.
- The ball valve was inadvertently closed, blocking the flow.
I bought a Zoeller A-PAK high water alarm that is rated for sewage basin applications. The Zoeller alarm is extremely loud and features a 9 volt battery backup in a addition to 120VAC primary power. The A-PAK alarm kit is shown below.
Install the Sewage Basin High Water Alarm
The high water alarm installation was easy following the Zoeller alarm installation instructions. I positioned the alarm float switch to trigger when the water level reached the bottom of the sewage basin outlet (right side of photo) to prevent waste water backing up in the underground pipes. (The evaporation rings inside the basin are from mud and rain water that partially filled the basin during construction of the home.)
The wiring leads through the rubber grommet in the sewage basin cover are:
- High water alarm signal wire – coiled cable hanging on the blue handle of the ball shutoff valve
- Sewage pump power cable
- Sewage pump on/off float switch
Sewage Basin High Water Alarm Wiring
The sewage high water alarm unit should be powered by a different 120VAC electrical circuit (separate circuit breaker) from that of the sewage ejector pump. The reason is so the alarm remains powered if the pump circuit breaker is tripped. I installed a new electrical outlet on a different circuit from that of the pump.
Fortunately I had ready access to an electrical junction box that I installed for the florescent light in the plumbing closet. It was a simple task to locate a new electrical outlet box and wire a duplex receptacle for the alarm:
The new wall outlet wiring is verified as correct with a receptacle tester. The two yellow lights as shown means the wiring is correct:
The sewage basin, sewage pump electrical outlet and high water alarm wiring. Notice the sewage basin vent pipe was disconnected via the PVC slip union and the two part metal cover on the left for easy access to the sewage basin and pump:
I verified the pump float switch and high water alarm were working by reaching into the sewage basin and lifting the two mechanical float switches. The sewage pump float switch turned the pump On & Off and the Zoeller alarm sounded respectively.
Short video of the basement bathroom sewage pump operation:
The basement bathroom toilet and sink/vanity are installed next, then sewage pump is tested with clean water in How to Finish a Basement Bathroom – Part 12.