Oh, just tell them you are not feeling well, and apologize, it'll be ok. I doubt very much it's actually the 'pump'. It should be a closed system, it just heats and circulates the air. Your complaints are not unusual for a new heating system Bex. Maybe sending them a card thanking them for it would be in order. Ours stinks if you turn it on after it's been off for a few months. That's normal, takes a good hour to lose the not-used-in-a-while smell. anyway, it's just electric stuff in there heating the air, should not be any fumes.

I do notice a major difference in the air quality when I use a cheap filter and a pleated filter though. I hate the regular filters, they recirculate dust, pollen, everything. The pleated ones keep the air much cleaner. Make sure you change the filter every couple months if you run it a lot.

I would send the owner a card thanking them. Give them a big 'oh never mind me' if they come calling, just say it was not one of your better moments because of your allergies.