I'm helping my heating tech install my PB105 and the existing in series oil boiler has glycol in it. We heard back from Harman that glycol is OK with the boiler but now we need to go buy X gallons to fill the PB105. I searched the web and Harman site for an hour and NOWHERE can this boiler water capacity be found. Harman's customer service told the local dealer it's 50 gallons. I look inside the boiler and seriously doubt it holds 50 gallons. Anyone know the answer?