Monkey's in the Furnace

Yesterday some funny things happened. Being only in Germany three months, my German is still a tad rusty and I think people really don't understand me when I chat to them.
I was at the Diffusion furnace when I asked the operator, "Die Ofen ist gut? Alle ist clau mit die Ofen?" However when I said this to the operator he looked at me and burst out laughing. At the moment I did not have a clue why but I thought it was cool and laughed as well. The guys there think that I am very funny and whenever I go there I shake there hands for 5 minutes smile and say something funny. They are probably thinking, man here comes the crazy Australian!
Later on I was explaining this to a friend and they aked me what I had said, well apparently "Ofen", the word for "furnace" is very similar to the word "Affe" meaning "Monkey". So apparently what I said to the guy was "Good day, how is the Monkey? Everthing is ok with the Monkey?"