This from the Welfare site......
" 11. Does living or working in another EU country affect my Illness Benefit?
You may continue to get Illness Benefit if you have lived or worked in Ireland and you have lived or worked, or are going to live or work, in another country covered by EC Regulations. (Please see above for the list of countries covered by these Regulations).
Going to another country covered by EC Regulations
If you get Illness Benefit from this Department and you intend to move to another country covered by EC Regulations, tell us as soon as possible. If you don't tell us, you may lose some payment or your payment may be delayed.
If you receive Illness Benefit in Ireland from another country covered by EC Regulations, you should let the country that pays you know if you move abroad.
If you go to live in another country covered by EC Regulations and become ill, you may apply for Illness Benefit from Ireland as long as you got Jobseekers Benefit from Ireland (before going abroad) or you paid your last insurance contribution in Ireland."