The purpose of a dishwasher relief valve is to provide an outlet for water in the dishwasher drain hose if the normal sink tailpiece or garbage disposal is blocked. The relief valve allows the water inside the dishwasher to leak out through the top, rather than being sucked back into the dishwasher, which can contaminate the water supply. Although dishwasher air gaps are more commonly installed, if your municipality requires the presence of a relief valve, it can be quickly installed with a minimal set of tools.
Things You'll Need
- Dishwasher relief valve
- Power drill and bits
- "Y" joint
- Hose lengths, 2
- Hose clamps, 4
Turn off the power to the dishwasher at the main circuit breaker.
Hold the relief valve in place on top of the countertop where you wish to install it. Trace around the base of the valve with a pencil. Remove the relief valve.
Use a drill to make holes around the perimeter of the marker on the countertop. Use the appropriate type of drill bit for the countertop. On a tile surface, for example, use a specialized tile bit. Take a chisel and gently tap at the edges of the hole until it snaps out of place. File down the edges of the hole with a drill.
Insert the relief valve into the top of the hole in the countertop. While continuing to hold the relief valve in place, secure the retaining nut beneath the surface of the countertop on the threads of the valve.
Connect a "Y" joint to the end of the dishwasher drain hose and secure by tightening the hose clamp with a screwdriver.
Connect another length of hose to one side of the "Y." Run the other end up to the underside of the relief valve. Secure both ends with hose clamps.
Connect the other end of the "Y" to the tailpiece on the underside of the sink or the garbage disposal. When connecting to a disposal, knock out the plug with a screwdriver before connecting the hose. Secure the hose in place with a hose clamp.
Restore power to the dishwasher.
Tips & Warnings
- To help secure two pieces of hose together, apply a drop of dishwasher detergent to the hose ends.
- The above steps are just a guideline. Always follow the instructions for your specific model of relief valve.
- Cheap and Easy Dishwasher Repair; Douglas Emley
- This Old House: How to Install a Dishwasher