The problem is if the boiler is leaking water the automatic fill valve is refilling the boiler jacket and cooling it down. The boiler is set to maintain its temperature in the jacket. When that drops the Becket burner will kick on to get the temp back up I'm the boiler.
This should nit be leaking ANY water its a closed system. Here is the basic possibilities of a leak.
Boiler jackets seals are not sealed in between the jackets.
The cast or steal jacket has a hole in it and is leaking on the floor
The pressure relief valve is going bad and dripping water out of it and on the floor
The seals on the circulator has bad seals.
The hot water lines or the cold water lines is leaking at a joint.
Thats about it.
Any leaking will cause the automatic water feed valve that's on the domestic water line hooked to boiler to open and add COLD water directly to the boiler and then it needs to re fire to bring up heat in the boiler so when you call for heat on the thermostat pre heated hot water is there on demand'
Fix leaks and this should solve the problem. If it doesn't then its another problem but the leak needs fixed first.
Signed 21 Boat
If I Helped To Answer Your Question Please Rate My Answer