Ok you obviously either have not read the sticky at the top of the page here about how Harmans work or it is not resonating with you, has not registered. Same with the included manual and instructions. It's ok, that seems to be normal around here.
Harman stoves through the ESP continually change feed rates *at will*, up to and including your high limit feed setting. In this shoulder season it's unlikely the stove is trying to put out max output for any amount of time. It's only during max output that the stove will feed at your limit setting. So ultimately right now it doesn't matter what you set the limit at regarding feed rate, 3 or 4 will work fine, so will 5.. This is not a manual feed system, your stove may well often be feeding itself at level 1 and 2 often this time of year. A good indication of feed being used is size of flame. If your flame is moderate in height, not totally filling your fire box then it is not being fed anywhere near max settings. If your flame is low, maybe even for hours at a time in mid day, it may even have gone into a maintenance burn rate, probably level 1.
"The one inch Burn Line "/ash line and it's total misunderstanding : The one inch burn line is a test procedure to set max feed rate for a given pellet at.. It's done at max temp setting ( turn the stove all the way up to the maximum heat range and plan on a good 30-40 minute burn) and you may have to open windows. After about 20 minutes of burning at maximum output start turning up the feed in 5-10 minute intervals until such a time as it achieves an ash line around 1/2"-1" from the edge of the burn pot. That is your max feed for that pellet. Note that some super low ash pellets may have a hard time getting a line to form as the very little and light ash is blown off the pot. No problem with all the crappy heavy ash box store pellets. When I conducted this test on my P61 using LaCrete pellets I ended up at just over feed rate 5. The manual says that feed rate between 3 and 4 is a good starting point as I recall. But those rates obviously are not optimum for max heat output for my P61 when burning LaCrete. Will the stove ever hit feed rate 5 on it's own ? Maybe on a cold winters night when playing catch up from a cold house . But my stove never ever has used pellets at the rate it did during that test, in that 35 minute test it went through 1/4 of a hopper of pellets. I ask you, has your stove ever used 1/4 of a hopper of pellets in 35 minutes ? Then it isn't running at max output to heat your house and neither is mine. And I ran that winter at feed rate 5 !! I'm sure it touched that feed rate periodically but not for any length of time. Last winter I ran with the rate set between 4 and 4-1/4. I tried 3 , as the weather got colder the stove took longer and longer to recover.
There are many stoves out there where you set the feed at say 3 then that is what the stove runs at. You have to manually set the feed. Harman is not one of them. By the same token, you cut the max feed capability back and then you turn your P 61 ( 61,000 btu max output) into a P50 ( 50,000 btu) or likewise, your 52i into a 40i by limiting it's available max output. For the most part none of these stoves run at max to heat or houses but they may need to to catch heating needs up. And then they throttle back, that's what the up and down flame thing is all about that we mysteriously watch our Harmans do.
