Need some advice. I have backflushed my Waterfurnace now that the heating season is done. I used three gallons of 5% white vinegar pH = 4. Ran 1/4 Hp, 16 GPM pump for one hour, then shut down for 1 hr. Only small amount of discoloration of vinegar. Restarted and pumped for 3 hrs. Purged heat exchanger with water. Back flush effluent showed some darkening compared to clean water. A few particles of black scale in bottom of pail. Looked like iron. Question: Do I need to use a stronger acid like Muriatic or pump longer with vinegar. I had expected more black deposits, my well tests for iron at 0.1 mg/L. Any advice is appreciated. Ken
I don't know what flushing solution you should use. Based on your other post it doesn't sound like you have much of a problem though. The water flow and delta-t look about right for that size unit. You mentioned a 20% increase in electricity, but that could be due to the weather, being at home more this year, etc.
Sorry for the delay in answering but I was away from the grid. I had noticed a black deposit on inside of some outlet piping I had replaced while revising the discharge to my ponds so I wondered if the heat exchanger was coated also. I had also replaced solenoid valve at outlet because it had black deposits inside and was sticking open occasionally. Thanks.
