Total Input Rating : The sum of the maximum Btu rating, as marked on the appliance by the manufacturer, of all appliances, not the nozzle sizes or actual firing rates
NFPA 31 Standard for the Installation of Oil-Burning Equipment, 2001 ed. https://www.nfpa.org/Assets/files/AboutTheCodes/31 /LPI-AAA_ROPagenda_06-09.pdf, (Std: Install of Oil-Burn Equip - Amer) {195 NFC}