You have a hot and cold line reversed somewhere. I had the a similar issue. Found it when I tore out the Master Bath. The faucet in the shower wasn't marked so you really never knew. But when I tested the new shower valve I found it.
First post: 9:37 AM. Resolved by 2:21 PM. 5 hours has to be a new TBN record... if anybody was keeping track.
Good to hear that you can take a hot shower again. :thumbsup:
Thought the issue had been resolved with a perceived problem at the washing machine selector valve, but......
It now makes more sense that it may actually be the toilet mix valve.
Output from the mix valve is full hot to toilet, when it should only be tempered water.
Cold is likely backfeeding internally.
I'm guessing that 40+ year old valve is kaput!
The hot feed to that valve is shut off now, so will see how shower goes tonight.
Will likely replace mix valve (nasty location) tomorrow.
Was the crossing of the hoses having an effect on your laundry?