Diesel boilers are small, powerful, and operate quietly without any smell or smoke. They are a perfect choice for warm-water central heating systems, especially for radiators. In New Zealand, over 10,000 diesel boilers have been installed in homes, with 5,000 of them being Firebird boilers from Central Heating New Zealand, known for their efficiency, strength, and dependability. 

These floor-standing boilers are slightly smaller than a modern washing machine and are usually found in garages or laundries. There are also external models that can be installed outside with a built-in flue. Diesel boilers need a fuel tank placed outside the house, with two size options available: 460 and 880 litres, which are slightly larger than two LPG tanks. These fuel tanks are set up on a concrete pad in a location that is easy to access for refuelling, even if it is up to 50 metres away from the boiler. Corestone Plumbing and Heating provide fuel delivery to both urban and rural properties in Otago and Southland and also offers services for extracting and replacing contaminated fuel.