by plumbbob »
Tue Dec 21, 2010 12:08 am
The explosion risk comes from the outlets being plugged up and water left trapped boils but can't expand and escape.
Providing the pipes are open then any water will boil off naturally without harm.
It is recommended to fill the empty boiler tank with kiln dried sand to ensure the heat is distributed so preventing the metal from becoming deformed by uneven heating which happens with solid fuel fires.