We live in a split-level house built in 1965; it has three residential levels plus a basement. Our bathrooms are on the upmost level, and the hot water heater is in the basement. The showers lose cold water whenever someone uses the kitchen sink, dishwasher, toilet, or bathroom sinks. The shower also loses hot water when hot water is turned on in any other fixtures. The problem does not appear to be related to the water heater, as we have recently replaced it (for other reasons). The plumbing and fixtures all seem to date from the original construction; we have changed only the shower heads to handheld models (separate hot and cold valves). Water pressure in the showers is not very strong either. Any thoughts? Thanks.

MTNC

Unfortunately your problem will not be easy to fix. When the house was built the supply lines were put in leading to each fixture. The further away you get from the main and the water heater the lower the pressure gets. Most installations start stepping down the size of the piping as you get further from the source, this helps maintain the water pressure. It appears your shower may be at the end of the line and losses significant pressure when out fixtures are opened. Water flows the route of least resistance so the pressure goes to the lower fixtures. Re-piping the supply would be the ultimate solution but that may be out of the question for a 40 year old home. You should remove and inspect the shower head and supply lines to insure there is not accumulation of debris or restriction.

My 20 year old, two story house had the same problems. When a toilet is flushed, or a faucet opened, instant cold water loss. So I changed the old shower system to a pressure balanced one, and problem solved.

It may work for you also.

See Here for some info.

Thank you very much. I will look into this.

If I will be solving this, I think I will pressure balance the system by looping it. It means I'm going to put a return pipe wher pressure would be balnce anywhere, I you can just pick up the last portion of the pipe and return it back to the source this is especially good if a booster pump is installed or a pressure tank. You can adjust the convenient pressure you want and the whole system will have the same pressure anywhere.have a good day everyone.

How old is your house and what material are the water pipes made of? Cheers, Tom

Ok. Since our pipe goes through all the floor levels like a spine, looping means opening walls at every level, right? Or is there any less drastic way to get this done?

Our house was built in 1965. The water pipes look like copper, but I am not sure.

Not necessarily opening it from every level. The last portion of the topmost level, the endmost part. The design would look like a fire protection system, where it has the same pressure in all areas. This is only one point of view. There are many ways available, you only use the most convenient one. Ask for more advice. This is only my point of view.