In my new house (built 1981), the hot and cold water are reversed in
the main floor powder room sink and the kids' bathroom tub/shower.
All other sinks and showers are normal. Both 'backwards' faucets show
hot on the left and cold on the right as normal, but have to be
It appears that the pipes to the reversed sink and shower are
installed normally. That is, the pipe on the left (as you face the
faucet as if you're using it) goes directly into the left/hot knob and
the right pipe directly into the right knob.
I was able to fix the sink by installing new steel-braided flexy pipe
(not sure what it's called) from the copper pipes to the faucet and
crossing them. But I can't do this for the tub faucet, where the
copper pipe runs directly into the faucet connections.
I would be very surprised then that the pipes were installed reversed,
which makes me wonder if the faucets themselves somehow mix the hot
and cold backwards. Are there faucets that do this intentionally, or
is there some way to configure a faucet to mix the water backwards?