The reason I asked is that if you’re throttling the heater inlet (LP-105/107) you could be intermittently starving the heat exchanger of flow which would result in high local temps on the coil, thus baking the oil and fouling the coil surface.
Not saying you are, just trying to cover all the bases.
And someone to watch them for a while. This ain’t rocket science. If you want to get serious about it, spend a couple of hundred dollars for a couple of little battery powered pressure and temperature data loggers and see what is going on.
when i find water where it isn’t suppose to be it is nearly always a goofed up piece of installed equip/system.