They did used to, not sure why they don't anymore, Enermax have a UK based RMA service too, which is unusual and very nice. I've used their power supplies for years, since the days they were 'THE' ones to buy if you were an enthusiast and wanted a good solid reliable psu. I've never had a problem with an Enermax myself.
My main machine now uses an Antec though, a Signature 650, which is beautifully made, fantastic piece of kit, but if I hadn't bought that for a rather good price, I'd have had another Enermax in a heartbeat.