My husband and I just moved into our first house (16 yrs old, with well & water softener). If he shaves, while I'm in the shower, the water in the shower goes cold. Is there any way to fix this? We'll be redecorating (new tile, toilets, vanities, etc.) two of the bathrooms (4 total) and are interested in doing this repair at the same time. Note: Same shower also "moans" during shower, requiring you to pull up on the shower knob in order to fix. Plan on replacing the shower faucet. We're not afraid of hard work -- he's worked in construction in the past.