Plumbing – Hot water comes out once toilet is flushed

hot-waterplumbing

I turn on the hot water faucet and cold water comes out. This happens everywhere around the house. Once I flush the single toilet that's on the first floor and wait 1-2 mins, hot water starts pouring out of the faucet. The second floor also has this issue where I have to flush the toilet on the second floor to get hot water anywhere on that floor. The hot water would continue to stay for about 1-3 days before having to repeat the flushing process again.

Read online that many place the blame on the water heater (which doesn't seem likely but would like to hear what you think) or the house having an old plumbing structure. If so, what can I do to fix it?
Thanks!

Best Answer

Alex here (some reason I'm locked out of the original account). It happen to be the 1 of my shower's valves. I noticed that the hot and cold water inlets were connected to the valve's sides labeled "shower" and "tub". I had to detach and weld the valve back to where the "shower" points up and "tub" points down. I also replaced the plastic cartridge where the shower handle would be placed just in case. With that, I now get hot water 24/7 without having to flush a toilet beforehand. Thank you all for the help!