Dan - We also have a 211S and only had a leak one time. We have not replaced the seals. The one time, I blame myself the way I parked the unit. The right front was low and the rain came from the left. My theory is that the rain poured on the outside roof of the slide ran against the unit and then forward - overwhelmed the seal. We had wet carpet, about as wet as spilling a half cup of water. Have made sure for all subsequent rains, the unit was parked with the right side slightly elevated. No problems.