It was an accident that we found out replacing Shower Valve fixed the “HOT Scalded Water while taking a shower because of someone flushes the toilet”. Our house is built in 1979, the pipes are getting old I’m sure, with the old shower valve, every time my kids flush the toilet while I’m taking showers, the hot water was unbearable. This year, after replaced the shower valve with Symmons Duron S-3602, the hot water is no longer an issue when someone flushes the toilet. We were going to get an estimate for water pipes replacement through out the house due to this problem and it was a lot of money. Well, at least Hot Scalded Water was the only problem we had.