I have a harman pb 105 that i have had for a few years now. Getting it installed and working was a pain. The local dealer near me does not really install these per say. They simply pipe them and by that only the intake and exhaust. So I had the dealer drop it off. I had a master plumber come to do the install and he was nice enough to connect it to power and plumb it up and such. I recently noticed that the overheat zone had never been connected. Course i noticed this because i just switched to a different brand of pellets that seem to burn hotter because several times now my boiler has stopped working and been flashing overheat. So i looked into it a little bit and i found a relay in box product which is a self contained dpdt relay so i figured i could have the boiler trigger that to fire up the circulator pump and open a zone. I got it all wired up but now the overheat zone is always on. Mind you the led itself isnt always on but the circuit is always on. The wiring i dont think could be easier really. 2 wires for the coil and then the switched wires. When i disconnect the blue wire from harman of course the relay shuts off but when i connect it it goes right back on. I am having a hard time thinking that its anything other than a bad logic board since there is so little that could be wrong. I am also not sure if i call the dealer if i will get any help with it at all since they wouldn't connect it to power to start with.