I've been using a Navien tankless water heater for about 5.5 years and I descale it every year with white vinegar. Recently (last Friday), after running the pump for about 40 minutes while descaling, I found an oily substance in the bucket. I flushed the water heater for over 15 minutes, but now the hot water smells oily and has some visible residue. The smell has gotten stronger over the weekend. I've tried flushing it with water and Dawn detergent, but that hasn't completely solved the problem. I've even bought new equipment because the old pump and hoses are covered in the oily substance. I'm really concerned about these questions: 1) Could the issue be related to the utility pump I used? 2) Has anyone else dealt with this before and what did you do? 3) What else can I use to flush the system? 4) Is my unit damaged beyond repair? 5) Has the substance made it into the pipes and what can I do about that? Thanks for any advice!
1 Answer
It's unlikely that the water heater itself is the source of the oil, since they don't use oil. The oily substance could be due to a malfunctioning pump or something else. I’d suggest running the pump on plain water and see if the same oily residue shows up again. If it does, that could point to the pump being the culprit.