Lite On Laars Lite 2 Heaters: 250,000BTU MV Heater "aquastat l8124a" Questions

...is the recomented settings for high and low limit control for the oil-fired water boiler model# LD-30PT. Honeywell aquastat L8124A 180 with a differential of 15 or 20. So 180 high and 160-165 on

...L8124A aquastat(new) and 3 zone pumps. My problem is an occasional short burn cycle(10 to 15 sec.) when the main zone pump shuts off. This does not happen when the other 2 zones shut down. DIFF iis ...