"I'm totally baffled by this"
Well, if you are then there's a good chance we are too. Help the pros out here by filling in the details of what you've got, when you got it, model number, fuel source etc and save everyone's time.
a pro -and this bugs me.
..imagine how the pros feel, having to give you free advice while having to waste their time asking you what you've got. Don't know how they do it. Does eveyone just assume we know what heating system you
have amongst the millions out there???