Alpine overshoots setpoint

Smith_2

I have a Burnham Alpine 105 w/ Sage 2.1 that won't begin throttling back until ~5F above the setpoint (and takes its time once it does start, so the supply temp may rise 10F or more above the setpoint).  The control board has been replaced out but it hasn't changed this behavior.



For now in order to prevent cycling during DHW calls we've substantially decreased the modulation and increased the diff above/below.  For heating though even with diff above/below increased, by the time it fully throttles back often the return temp has caught up with the setpoint (before throttling it will have a delta T of 10-20F).



Any suggestions?