Most systems have design temperatures of around +10°…meaning they’ll keep the floors ice free down to that temp. Not too many customers want to wash when it’s that cold. And most operators don’t want to spend the money on gas to keep the floors ice free at those temps.
First thing to look at is the tube bundle (heat exchanger). Raypak boilers are susceptible to sooting caused by insufficient combustion air…especially when installed in a tightly sealed equipment room. Over the years, soot build up on the tube bundle can become so heavy that it insulates the tube bundle from the burner tray, dramatically lowering the Btu output.
This condition also lowers flue temperatures resulting in condensation which drips onto the tube bundle. That acidic condensation then erodes the boiler’s internals, tube bundle, burner tray, refractory, etc. The burner tray will also start to collapse due to the high combustion area temperatures. Bye-Bye Boiler!
Take a look at the seams of the flue. Traces of condensation will be a good indicator of insufficient combustion air and sooting.