Hello I recently bought a house built in the 30s. The hot water in the upstairs bathroom was working great when we first moved in now it only gets hot when we turn on the shower down stairs. What would be causing this?

Thank you

Does the upstairs bath also have a tub or shower? If so how do they act, just like the sink? Is the sink faucet one handle or two?

The down stairs has a tub and it is one handle the up stairs is just a shower also one handle.

Also the sinks and every thing else in the house get very hot still its just the upstairs shower.

Still not sure what you got, "up stairs is just a shower " but there is a sink too, right? Does it get hot?

Still not sure what you got, "up stairs is just a shower " but there is a sink too, right? Does it get hot?

Up stairs sink gets hotter than the shower but I believe it was hotter before.

One handle shower vlaves are cartrdiges or ball valves, yours is clogged. Do you have the skills and desire to take the valve apart, any idea who made it?

One handle shower vlaves are cartrdiges or ball valves, yours is clogged. Do you have the skills and desire to take the valve apart, any idea who made it??

I believe they are delta and I know they are both balled. I have taken the top one apart hoping a flush of it would do any thing. It did not. I only recently figured out if I turn the shower on downstairs and then run the upstairs shower it will give me hot water upstairs like it use to.

It's really late where I am but Tom starts very early in the morning. Maybe he will have more ideas, that downstairs shower making the upstairs hot has me plexed.