Pretty long time passed since you asked that question. It seems that Elo touchscreens can work for several years without any need in maintenance work. Elo provides three-year warranty, plus the MTBF value is about 50 000 hours. Besides, it depends on the model: some of them have only 18 month of warranty, like this model - http://hardware.nl/touchscreen-monitor-/elo/e114849.html
But the company can add another 18 month of supported warranty if you pay more.