Going to plumb my whole house looking for best way to do it? I have 2 bathrooms 2 hot water heaters that are hooked together. Problem right now if taking a shower and someone uses water anywhere else in the house shower gets very cold. So does anyone know the best way to pipe this or maybe have a good diagram. I will be using all pex. Right now its copper, cpvc, and pvc
- EdwenaLv 72 months agoFavorite Answer
The problem is a pressure imbalance between the cold water and hot water pipes in your house. The source pressure for both the hot and cold water is the hot water heater. That is the inlet cold water and the outlet hot water. If you will make a manifold in those lines at the heater and then run your cold and hot water lines to each utility (each bathroom, kitchen, etc) then the pressures and volume will stay balanced and there will be no change in the temperature. The problem you are describing is because the cold water and hot water comes from different sources, and therefore is a different pressure. Like the cold water is tapped near the pipe entrance and the hot water heater is over on the other side of the house 75 feet away. I don't know anything about PEX, but don't put it anyplace that you can't get to it to replace it. Also, you should still use not less that 3/4" size to any appliance to have a good supply of water. And it will freeze and rupture. If you are putting in water lines that are permanent and for a life time, you have to use seamless copper tubing inserted in a black flexible irrigation pipe (butyl?) Run that under ground from the manifold at the heater to each bathroom. For both hot and cold water. Then come up at each bathroom on an interior wall, and use hard, copper pipe and fittings. You might also consider a tankless hot water heater, especially if you have gas or propane. A whole house tankless hot water heater is probably superior. But it has to be sited correctly. So the rule to solve your problem is simple. Run 2 parallel lines (hot and cold) from the hot water heater (inlet and outlet) to each bathroom and terminate the lines at that appliance.
- Spock (rhp)Lv 72 months ago
the symptom you describe is caused, imho, by too small piping -- especially on the cold water line to the hot water heater(s). Other possible causes: inadequate pressure from the utility. Too small piping from hot water heater to showerSource(s): grampa
- GTBLv 72 months ago
Slow down! Before you change all out, look at pressure equalizing valves for the shower. A pressure equalizer is designed to maintain the hot:cold water ratio even when the demand for water elsewhere in the house fluctuates markedly and it is designed to address the matter. Without pressure equalizer valves, all the other plumbing will be of no value; do the pressure equalizer first and you may not need a lot of re-plumbing. PEX is a good product.