Most faults like this, Although they have the potential to be very dangerous (even fatal)
Are often a simple fix if you have the correct knowledge and equipment to test first, diagnose, fix, TEST AGAIN.
it could be as simple as a cable that is not connected, or broken.
a fault with the distributers supply to your house could also be the cause (they will fix that for free same day)
A professional electrician will tell you what the problem is and who/how it can be fixed and made safe.
depending on how your house is wired and plumbed, it MAY BE THE CASE that if you touch one of the items that is giving you a shock AND a radiator/sink etc. AT THE SAME TIME, especially with wet hands. THE SHOCK COULD BE A LOT WORSE. a couple of hundred people die in the uk from similar accidents in the uk each year.