Water Sputtering After Tank Fill - New (Edited) Information

2016 S-Max. I have just filled the water tank after winter storage (with the trailer heat on - though I had drained the water system anyway). Now water sputters when faucets are turned on. BOTH the hot AND the cold. Kept doing it for at least a half-hour before I gave up. The hot water boiler IS ON. The hot water sputtering is accompanied by quite low flow. Cold water faucets seem to be flowing at a mostly normal rate between sputterings. All the valves next to the Alde are in the correct position and aT@B tech yesterday said everything looked okay to fill up the water tank for our planned Sunday trip.  WHEN I HOOK THE WATER SYSTEM UP TO AN EXTERNAL SOURCE THE HOT AND COLD WATER IN THE T@B WORK GREAT - WITH NO SPUTTERING!   Any ideas how to fix this? The campground does not have water hookup so we need to use water from our tank.