I live in a house that is 6 years old. Three Tubs with Showers. The Showers take about 3 minutes or so to get hot then they stay hot.

The tubs start hot right away then in about 30 seconds it goes warm then cold and you can never get hot water back. Can't figure it out. Any suggestions?

What's the brand name of your mixing valves? Do they have temp control or skald guard features? Let me know, Tom

All of my valves are Taco. You might have to dumb this down for me a bit. It was my assumption (though it probably is incorrect) that the hotwater feed came up from the furnace in the basement on one pipe and then split when it arrived at the bathroom. One direction to the tub another to the shower. Same feed though going to both thus the confusion for why it would be hot at one location and not the other. Is it the same pipe that feeds the showers and bath? It must be, no?

All of my valves are Taco. You might have to dumb this down for me a bit. It was my assumption (though it probably is incorrect) that the hotwater feed came up from the furnace in the basement on one pipe and then split when it arrived at the bathroom. One direction to the tub another to the shower. Same feed though going to both thus the confusion for why it would be hot at one location and not the other. Is it the same pipe that feeds the showers and bath? It must be, no?

And normally you would be correct, nut upon researching Taco mixing valves I find that they are more complicated then the average mixing valve. Do you have a Taco Hydrophonic System? Now I need model numbers and all the information and details you can give me. Thanks, Tom

I have replaced the guts to my symmons valve and I'm still not getting water out of my tub, but I get hot water everywhere else in my house?