I agree with BM.........unless, it's a VERY new house built under the newer 17th edition Elec. Regs. The house may have had some electrical work lately which would have necessitated the whole thing being brought up to the new standards.
Sorry about all this waffle, but today, ALL circuits have to be RCD protected.
Kassee ....... perhaps you have an RCD as your main incomer switch?
Anyway, back to the plot. Assuming it's an RCD that's tripping out, most likely to be earth leakage. Elec cookers, and freezers are the most common causes of "nuisance tripping". During their normal use, they leak a small current to earth ........ sometimes enough to cause a 30ma trip to operate.
I had this recently. I did a test on their RCD, and it was operating at around 20ma instead of 30ma. I just replaced the RCD and all was fine.
Of course it could still be the iron. Process of elimination. Has it tripped without ironing?