B737-700
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 150
Confusion; Time Pressure; Workload; Troubleshooting
Aircraft Equipment Problem Less Severe
Flight Crew Returned To Departure Airport
Aircraft
We got a Cabin Altitude warning horn and light passing 27;000 feet MSL. I observed the cabin altitude at 10;000 feet on the gauge. We complied with the boxed items and ran the checklist on the QRC and continued with the QRH. The cabin seemed stable at 10;000 feet. An idle descent was initiated with ATC giving us a clearance to 10;000 feet. Communications between the Captain and FO (First Officer) with the masks on was difficult. The cabin was controlled well in manual. We elected to return to ZZZ. The return and landing were uneventful. The passenger oxygen masks never deployed and the cabin was never observed above 10;000 feet. An unusual note: at numerous times during the return to ZZZ; the cabin altitude gauge read either 40;000 feet. or 23;000 feet. This led to significant confusion. We were confident that this reading was in error because we were well below 10;000 feet MSL as confirmed on all three altimeters.
A Boeing 737-700 Captain reported a pressurization problem during climb that necessitated a descent and return to the departure airport.