When my boiler calls for heat and the blower kicks on, it is only a matter of minutes before it shuts down. My low temp cut in is set at 160° and my high temp shut off at 180°. So I'm raising my water temp 20° in about 8 to 10 minutes tops at this time of year. A little longer in the deep winter. Check your flue pipe to be sure you don't have a blockage. You need a good draft to create good heat.