Slow and stopped shower draining
I have a 2014 Tuscany 40 KQ in which the shower periodically drains slowly or at times ceases to drain. I have replaced the two "Air Admittance Valves" (one under the kitchen sink and the other behind the washer/dryer) which helped but the problem persists. There is no vent to atmosphere through the roof, the only vents in the gray water system are the AAVs. Would appreciate any "fix" ideas! Thanks.