The 1300/1400 series Delta tub/shower controllers sometimes did exactly as they pleased. Then you would try to adjust the hot/cold valve controls and the adjusters would start leaking. Cutting out a hole in the wall and then cutting out the old valve and replacing it is the only cure. This unit does the job in an excellent manner. You will have to change the cartridge for the new valve, but when finished you will have many more years of delta faucet to use. The two legs on the old cartridge are too short to use in the new valve.