Pumps In General
If a check valve is used, we recommend drilling a vent hole in the discharge pipe. This hole is located in the basin between the pump and check valve, usually a few inches above the pump “on” level but below the pit cover. The vent hole will prevent air-locking from occurring.
For submersible pumps, depending on the specific model, warranty could be either two years from the date of purchase, three years from the date of purchase, or five years from the date of purchase. Proof of purchase is required. Abuse or misapplication can void this warranty. Check with individual products for specific warranty information.
Under normal service conditions, we feel that the unit is designed for a 7-10 year service life. But during this period, the pump may require periodic servicing.
In a sewage system a check valve is required to prevent the sewage from draining back to the basin. They are usually recommended for all other submersible pump systems, but not required.
This is called short cycling. It is a function of the basin diameter and the “on/off” pumping range. Since the basin is in the ground it is unlikely that it can be enlarged. If you have an automatic unit which has a self contained float switch the “on/off” pumping range cannot be adjusted. But with a nonautomatic unit controlled with a pump switch you can have flexibility in the pumping range adjustment. Short-cycling can decrease the service life of a switch assembly. If this occurs, an automatic unit can be converted by using a long-cycle kit (P/N 10-0001) or by using a non-automatic pump with a piggyback variable level switch, which will expand its pumping range and decrease the amount of short-cycling. Installing a check valve in the discharge line will help decrease short cycling.
The noise you hear is the check valve closing. This is called “water hammer”, and it is the slamming effect caused when the flow reverses in the discharge pipe after the pump stops. Though it is more annoying than troublesome to your system, you can eliminate this noise by using a different kind of check valve. Check out our Quiet Check Valve.
The pump is probably air-locked. Check out our short video about Airlock Prevention!
If you have a check valve in the system, make sure your 3/16″ (5 mm) vent hole has been drilled and is not clogged. If it has not been drilled, disconnect the pump from your power source, and drill the hole (see questions #1 & 4).
If the vent hole solution is not the problem, remove the pump from the pit after disconnecting the power and piping, and make sure the impeller rotation is not being restricted.
If you have an automatic pump with an integral float switch, the switch assembly is malfunctioning, and the switch, switch arm, and case gasket should be replaced. The average switch life is 4-7 years, but it may vary depending on the application. If you have a non-automatic pump with a variable level float, it may be hung up on something or need to be replaced.