Hi/Lo settings for boiler

I have a relatively new (7 years) oil-fired boiler with an aquasat control that heats two zones and my domestic hotwater through the internal coil.
I live in Maine (brrrrrrr)
I'd like to know what the most efficient hi and low setting are for the aquasat. My furnace guy set them at 190 and 170 -- but I don't trust him completely because he sells me my oil as well.
Are there any rules of thumb on this?
As a rule, I tend to trust the professionals, but in this case I'm curious if there are others out there with different information.
Thanks,
John
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snipped-for-privacy@gwi.net (John Gold) wrote in

When I bought my house, mine was set to 140 - 120. I have had 2 different techs advise me to change it to 180-160 (which I have)
Chris
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Why not get a differernt heating guy if you don't trust this one?
Hotter temps provide more rapid heating, but also increase the risk of burns.
Hotter temps are also very slightly less efficient (more fuel) cause the flame is heating a hotter boiler. So the flue gasses are slightly hotter.
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Christopher A. Young
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I'm really getting tired of telling you to borrow a quarter so you can buy a clue!

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Then don't.
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Christopher A. Young
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