Is this when using a faucet/shower/toilet?
When no demand ----nothing being used?
When using......could be discharge hose vibrating/pump vibrating-----hot water heater outlet check valve shuttering
When not being used.....pump internal check valve leaking causing plumbing system pressure to drop/pump starts--increases pressure then stops (short cycling)
*any LEAK will cause drop in system pressure---the more frequent the short cycling the bigger the leak
Is it time for YOUR Medication or Mine?
Dodge 3500 w/Tractor Motor & NUWA 5vr
US NAVY---USS Decatur DDG-31