Hi all

My first post, I will try to obey the rules.

I have rift sawn white oak floors on radiant heat panels. I was away for the winter and had the heat in the house at 50 degrees which I monitored daily. Did the same thing last winter with no problems. Got back last week, turned heat on to normal and noticed a few days later odd looking stains on the wood. On close inspection there seemed to be water beading on the top of the wood. I am not sure if the radiant heat pex is leaking - seems unlikely since the stains are appearing in different rooms that have different heat zones. Is it possible that somehow the heat gradient between the 50 degree air room and the 90+ degree water flowing thru the pex when the heat is on may have caused condensation below the white oak and is now being forced up thru the wood since the heat is on? Any thermodynamic guys out there to explain this? One more data point - I believe the basement under the 50 degree house was warmer than the house itself (55-60?) because of the heating plant and copper piping in the basement. I have some photos but do not see where to attach them to.

Thanks for your time reading this