My new sump pump is pre-plumbed with 1.5" PVC, but my existing discharge line is 2". Is there any problem with connecting the 1.5" pump outlet to the 2" discharge line using a flexible Fernco coupling on the vertical section of the line? The check valve will be below the Fernco connection point, right at the base of the pump.
Update: I installed the new sump pump with the flexible 1.5" to 2" fernco coupling, and it's working like a charm. Thanks for the answers.
Best Answer
Not a problem.
FWIW, I installed the check valve above the coupling so that it would prevent draining when I remove the pump for service. The valve I used is threaded, so I can still remove it if needed. No problems after many (20?) years of service.
Tip: Put the pump in place without the coupling and mark the PVC pipe to indicate where the coupling should be positioned to center it over the joint. That removes any worry when reassembling the plumbing.