Note
Due to the precision of modern modulating boilers it is important to pay special
attention to gas pressure regulation.
Important: Check gas supply pressure to each boiler with a manometer or other high-
quality precision measuring device. Pressure should be monitored before firing the
boiler, during operation throughout the boiler's full modulation range, and after the call
when the regulator is in a "lock-up" condition.
Pay special attention to retrofit situations where existing regulators may have an over-
sized orifice and/or worn seats, causing pressure “creep” and high lock-up pressures.
A high quality regulator will maintain constant pressure above the boiler’s minimum
specification at all firing rates, and will not exceed the boiler’s maximum pressure
rating when locked-up with no load.