We moved abroad in 2007 and used a letting agent to manage the property. Whilst they have not been brilliant in making me aware of things such as BER, property tax etc.. they have been good in the general run of the mill stuff such as handling issues around heating, plumbing etc.. and any tenant queries.
Bare in mind - what are you going to do if you get a call at 2:30 in the morning because there is no hot water in your house in Dublin-.
Plus you will be amazed at the type of things that go wrong once you leave the house, since we have left the oil burner has broken down, hob stopped working, washing machine bit the dust, heating element in water cylinder went and other stuff. It was very handy to just get an email from the letting agent regarding the issue and to have them deduct the cost at the end of the month and forward on the invoice (so you can get it back off the tax man later).
Also the tax implications are important to note, it is important that someone in Ireland is responsible for paying the tax on the rent, Revenue demand an Irish resident or company be responsible for this- this is a big thing to ask a friend or family to do. The letting agency do this as part of their service.
PM me if you want details on the company I've used. Like I said, not fantastic, but they have done a decent enough job to have been worth it.