Sensing tube condensate

Wonky

I have had an A.O. Smith GDHE-50 condensing water heater for about four years. When it works (almost all the time) it's great. It occasionally develops a blower prover failure, generally when the weather is cold and damp and especially if we haven't used it for a long time (like after a weekend away). I read the service manual and did a little other research and realized that the failure is due to condensate buildup in the sensing tubing that connects the blower prover switch to the heating unit. I usually can unhook the tubing, let it air dry and then get everything to work. The other two sensing tubes (one goes directly to air intake, the other to exhaust) never seem to be a problem. Today we returned from an extended vacation, and it's been typical late-December weather here in New England while we were gone. When I checked the tubing this time when the machine gave the same error, I could actually see the buildup condensate--it was a good 1-2 ml of water. Is there anything I can do to prevent this? If it happens intermittently and is easily fixable do I need to do anything?