Navien NPE-180A, loud humming

[Jakester]

We had a Navien NPE-180A installed almost 5 years ago and recently it started making a loud humming / whining noise when the hot water is used, could the heat exchanger be doing this?

Another question this time I would like to do the system flush myself and was wondering if there is any benefit of using cleaning vinegar which is 6% instead of the 5% while vinegar?

 

[Reach4]

Another question this time I would like to do the system flush myself and was wondering if there is any benefit of using cleaning vinegar which is 6% instead of the 5% while vinegar?

Interesting question. Not only stronger, but a bit cheaper. Should I use it when I sanitize my well some time? I already bought 2 gallons of food white vinegar for under $5 for the pair. Should you worry because it does not have food certifications? I have no answer for you, but I am glad that you brought this up.

https://www.walmart.com/ip/Heinz-Cleaning-Vinegar-6-1-gal-Jugs/21570071

I expect that instead of "Heinz Cleaning Vinegar 6 - 1 gal Jugs" the descriptions should read
"Heinz Cleaning Vinegar 6% - 1 gal Jug"

 

[Sponsor]

 

[Jakester]

No one using cleaning vinegar?

 

[Jakester]

Just wanted to update my experience. I ran 3 gallons of Heinz Cleaning Vinegar (6% acidity) through the system for 2 hours and now the water heater is back to being quiet just like when it was new.