This Old House plumbing and heating expert Richard Trethewey solves the mystery of hot water from the cold-water faucet. (See below for a shopping list and tools.) SUBSCRIBE to This Old House: http://bit.ly/SubscribeThisOldHouse Shopping List: - pressure balancer Tools for How to Repair a Shower Anti-Scald Pressure Balancer: - screwdriver - needle-nose pliers About This…