I have a new shower, and a new well. My shower worked fine for about 3 weeks. Went to turn on the hot water and it wouldn't turn on. The cold side will turn on just fine. Does anyone know why this is happening?
Most likely, when either the new well or new shower valve were installed, debris in the line was dislodged and is now blocking the hot water side of the valve. Turn the water off, remove the cartridge in the new shower valve, and with another person, turn the water back on for about a minute to flush the lines. I say with another person, because if you turn the water on with the cartridge removed and no one there to catch it with a 5 gallon bucket, water will shoot across your bath. You may be able to do it by yourself if your new shower valve has water stops built into the valve (they will look like set screws to either sive of the valve body) but most valves from the home centers do not have this feature. It would help to know what type valve you have installed, but you may be able to figure it out yourself. If it was installed by a company, I would call them and request a service call (it should be free since it is so new)