Boiler leaking from insulation

[colonel]

I have a Isoterm Basic boiler and its leaking just from the insulation layer. The rubber gasket looks dry. I don't want to open the window to check what's inside because I afraid it wouldn't seal back.

As I understand the tank inside should be welded. There should no any other connectors inside. What could cause the leak then?

[alamoana]

Dear Colonel, there are a few connections to the inside of this tank. Two cold water and 2 hot water connections. There is also a connection for the heating element. I believe this tank does NOT have an anode. It could be leaking at any of these points if they worked loose, or it could have developed one or more pinholes, depending on its age. Good luck