Just be careful – if the silver solder is of the type used by refrigeration / air con engineers, its only OK for copper WHICH IS NOT FOR BOILER USE or even for STEEL. It looks a bit more coppery than the whiteish yellow of easy flo type silver solders.
If used on boilers, the steam erodes the joint. If used on steel, the joint looks good, but has no strength in it.
If you are doing boiler work get the proper stuff.
BobH