I used Reckingers for a furnace inspection. The guy did one quick salt test and It seemed like he knew it was going to fail before it failed. He then shut off the gas and power and told me it was very dangerous. They called with a very high repair quote and tried to sell me a new $4k model. I had another company out and they spent 45 min cleaning, inspecting & testing with a meter and said it was fine. I also did a web search on the salt test and I suspect it was not done properly. I found comments about it being outdated and that it might not even work on my type of furnace.
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