Would this irritate you?

Good manners would never irritate me...

Obviously not being in the situation to hear the exchange but no I'd say its polite? Maybe next time dont say a word or grunt!?

Yes it would irritate me. its too cap-in-hand / hand wringy.

Er no, I don't think so. Seems like an odd thing to pick up on.

Mind you, on holiday in Florida we we chuckling about how often the waiter/waitress said "you're welcome", until we realised it was always in response to us saying "thank you" ? We tried to tone it down after that, but it was difficult as it's so ingrained in us.

It depends. If it was how my MIL does it - "oooooh thank you" half way through a sentence while you're just pausing for breath - then it would annoy me as she clearly isn't listening properly to what I was saying.

Or maybe he wants a bit more feedback from you "ah right, yes I can see how that would work" or "no, it won't work like that because we need to do x,y and z too and it would clash"?

Can't tell - would have to be the person being told thank you all the time to know, I think. My boss says sorry to me constantly. For daft things - like I buy tea but she's not there to drink it or I remind her to call someone back for the second time. Then I feel I have to say that's alright. That irritates me and I also feel a bit daft letting her know the thing she did was ok by me as I'm sure she doesn't need my approval. Does that make sense?

Thanks all (see, I AM polite!)

Chicken yes that does make sense. Nick I think I can see what you mean and maybe that's it. He says if I said "Cheers" it would be ok but I don't say cheers, ever.

Lady Falafel, yes I can see that too. I usually do have plenty to say as well, but also finish it off with thanks if he's taken time to explain something to me.

To try to give a context, we'll be talking about an issue- say boiler maintenance for example- and I'll query some part of it and he'll almost always take time to explain what he means, by drawing diagrams of the whole heating system on my whiteboard, explaining where the pumps are or whatever. When I thank him it's because he's given me useful information or given up some of his time. He says it's the only thing that irritates him so I should be grateful for that really!