Eccotemp CE-L10 Portable Outdoor Tankless Water Heater, 37 mbar. Comes complete with Ireland propane tank  adaptor if required. 
Fully fitted in NI and Border counties for £245 
producing up to 11 litres of instant hot water 40 degrees and above. 
No electric needed, just gas and water source. 
The Eccotemp CEL10 Portable Propane Tankless Water Heater is the original and best-selling portable water heater on the market today.