"H" wrote in message
news:ExR%f.19$JY5.4@trnddc01...
I had my bathroom refurbished about 5 years ago. All is well, except for
one new thing that started last night.

When I run the hot water, the pipes apparently start to shift in the wall.
This has not happened prior to last night. It is loud. It sounds like
the joists are being pried apart while the water gets hotter, and a very
loud drip while it is cooling down. When the water cools in the pipes, the
sounds stop.

Should I worry?

Thanks.
Try the simple fix first. Shut off the water to the house. then
open all the fixtures and hose bibs drain all the water out of the system.
Refill the system and see what happens. the usually pipe air chambers into
the system. in time the water absorbs the air so you have no cushion
anymore.Try that might help may not cost nothing. Can you describe the
dripping sound better? also when you hear the dripping see if the sound is
coming from the hot water tank.