IMHO this is not necessary and makes opening in spring more work. The TM is set up very nicely for winterizing. If you open all faucets before opening all 4 drains under the TM everything should drain fine assuming TM is close to level. If you want to be extra sure, Close faucets leave drains open and connect shore water supply ( not water tank fill) to a compressor and blow air through the lines. CAUTION I would not exceed 20-25 psi. Don't forget to remove the kitchen sink spray head if you have one. I also leave both black and gray drains open a little just in case. Got to zero here last winter and no issues.
|