"Speedy Jim" wrote in message ...
PeterL wrote:

For a period of time my the hot water in my master bathroom shower won't
heat up to the usual temp. All other faucets in the house, including
the
bathtub (separate) next to the shower, and two other showers, all heated
up
properly. But just as I was about to call in a plumber it fixed itself.
E.g. the water gets hot again.

I am thinking this has to do with a possible blockage, which somehow
cleared. Should I still call in a plumber to look at it? This is
probably
going to be a major job, involving breaking through the walls.

Is the shower control a single-handle style?

Yes.

Could be a problem
in the cartridge leaking cold into the hot side.
Could also be a "scald-guard" type with a sticking mechanism.
Neither problem involves knocking walls down...


Would these problem somehow "fix" themselves?

Jim