Rob's advice to fire the boiler more often may be the answer. My boiler has been running great with the a 30 minute outfire time with a 2 minute stoker time. It keeps the chimney warm enough to have a draft. I don't know what settings an AHS boiler should have, but the rest of my settings are 4 teeth, 4 air, 140 low limit, 210 high limit, 10 differential, no foil on baro damper and the domestic water superstore zone wired to not automatically call on the stoker. The stoker only comes on when the boiler low limit is reached.
The advantages with the LOGO are;
It saves fuel and wear and tear on the boiler by resetting to 0 time anytime there is a natural call for heat.
It saves fuel and wear and tear by the ability to set longer outfire times in the winter.
It has a circuit for a dump zone to prevent outfires.
It counts daily outfire and dump calls, allowing you to tune your stoker to enough stoker time to prevent outfires, but not so much that it has to dump.
It has a circuit for controlling a draft inducer if you need it, saving fuel by only running the draft reducer when required and then only bumping it intermittently to keep the fire going.
It alerts you to long term maintenance intervals for chimney and boiler cleaning.
It alerts you if you forget to take the ashes out.
It displays daily stoker run minutes so you can compare with heating degree days to check the system setup or fuel efficiency.
It does all this in the same type of non-volitale memory as the Honeywell new triple aquastats.
I am going to load the program for other people and would be glad to do it for you.
I can provide a wiring diagram.