Hi Doby
I would like ta add to your reply and ask a few questions. I hope it is OK.
buenf.
Are you serviced by a "water company" or do you have a private well?
If on a well the problem could be with the settings on your pressure tank. Consult with a well drilling/installation company or a qualified plumber.
If you are serviced by a "water company" the problem could be from the installation of backflow prevention devices. You should have been warned in advance of the installation of these devices and been advised of your need for a "thermal expansion tank" to prevent damage to the plumbing system in your house.
http://www.delcowater.com/InternetPa...ansioninfo.htm
Call your water provider and see if this is what has happened. If this is the case then you will need to install a Thermal expansion tank. If you have the ability and tools it is a simple task but you need to follow the manufacturer's instructions or the device will be worthless!!
If you do not have all the tools required then you need to call a competent plumber ASAP.
Good luck,
Marc