MC2: 10/03/12 Page 17 of 90
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
Modulex MLX Series Gas Fired Boiler System
Operation and Maintenance Manual
Chap 2: General
Description
2.7 Boiler Freeze Protection
Should the boiler water outlet temperature decrease to less than 44.6°F (7°C), the system pump will start.
Should temperature decrease to less than 37.4°F (3°C), all heat modules will start at minimum output until
the return temperature reaches 50°F (10°C). Such a protection device is exclusively for the boiler. For the
protection of the whole system, a second freeze protection thermostat is necessary to switch on the
heating system pump.
NOTE
If glycol is used as antifreeze in the boiler, a back flow preventer must be
installed in the make-up/fill line.