what's happening is no water circulation, the top hose should be measurably hotter - has it worked since you last had the stat out? sounds like there may be an airlock at the thermostat - or you got it in backwards?
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics
