Harman stoves have two modes of operation, "stove temp" and "room temp". By turning the mode knob either up or down you select your mode. This knob is a multifunctional knob as it not only changes between the two operating modes but it also adjusts the fan speed for the distribution blower.
In the room temp mode the stove is monitoring the room temperature via the room thermistor probe. As the room cools or becomes warmer the stove is able to monitor progress and modulate the stove's heat output to ramp up or down the feed to meet demand respectively. Regardless of the distribution fan setting, the thermistor probe will control the stove's output, even ultimately turning the stove on or off as required.
If you choose to run the dove on the "stove temp" mode, the only sensor controlling the stove is the ESP (exhaust sensing probe). Stove temp mode uses the numbers 1 through 7 on the inside of the temperature dial. In this mode the stove is seeking to achieve and maintain an exhaust temp between 350 degrees (#1) and 500 degrees (#7). Here's the issue....
The mode selection knob still allows the user to control the distribution blower but the stove does not know what setting the blower is at. The amount of heat that is extracted from the heat exchanger varies according to how much room air is being transferred; the higher the fan setting, the more heat that is removed from the exhaust, thus will affect the ESP reading.
If you run in stove temp, simply adjusting the room distribution fan up will cause the stove to consume more pellets!
Here was my test on my P61 using 40lbs of LaCrete pellets in two separate runs:
First run was on Stove temp mode setting #5 moderate fan (middle), 40 lbs in about 12 hrs
Second run was on stove temp mode setting #3 with fan on high (all the way up), 40 lbs in about 9 hrs
Even though I adjusted down my heat setting, as the manual would suggest, I got less burn time out of 40lbs by using the high fan setting.
For both runs my feed rate was set to 4
I had always wondered about this scenario and finally got a moment of clarity over the weekend when I filled the hopper Friday about 7pm and at 8 the next morning it was empty and sputtering out. I filled it again but this time turned the fan up and kicked the heat setting down...by 6 that night the stove was completely out again.
I've had many customers over the years complain that for whatever reason, the stove just chews through pellets at times and at other times seems fine. It was always my assumption that this was the culprit....so no longer a myth.
Any of you out there care to back this theory I'd love it...especially someone with hardwood pellets, though I don't know if that would really make a difference.
In the room temp mode the stove is monitoring the room temperature via the room thermistor probe. As the room cools or becomes warmer the stove is able to monitor progress and modulate the stove's heat output to ramp up or down the feed to meet demand respectively. Regardless of the distribution fan setting, the thermistor probe will control the stove's output, even ultimately turning the stove on or off as required.
If you choose to run the dove on the "stove temp" mode, the only sensor controlling the stove is the ESP (exhaust sensing probe). Stove temp mode uses the numbers 1 through 7 on the inside of the temperature dial. In this mode the stove is seeking to achieve and maintain an exhaust temp between 350 degrees (#1) and 500 degrees (#7). Here's the issue....
The mode selection knob still allows the user to control the distribution blower but the stove does not know what setting the blower is at. The amount of heat that is extracted from the heat exchanger varies according to how much room air is being transferred; the higher the fan setting, the more heat that is removed from the exhaust, thus will affect the ESP reading.
If you run in stove temp, simply adjusting the room distribution fan up will cause the stove to consume more pellets!
Here was my test on my P61 using 40lbs of LaCrete pellets in two separate runs:
First run was on Stove temp mode setting #5 moderate fan (middle), 40 lbs in about 12 hrs
Second run was on stove temp mode setting #3 with fan on high (all the way up), 40 lbs in about 9 hrs
Even though I adjusted down my heat setting, as the manual would suggest, I got less burn time out of 40lbs by using the high fan setting.
For both runs my feed rate was set to 4
I had always wondered about this scenario and finally got a moment of clarity over the weekend when I filled the hopper Friday about 7pm and at 8 the next morning it was empty and sputtering out. I filled it again but this time turned the fan up and kicked the heat setting down...by 6 that night the stove was completely out again.
I've had many customers over the years complain that for whatever reason, the stove just chews through pellets at times and at other times seems fine. It was always my assumption that this was the culprit....so no longer a myth.
Any of you out there care to back this theory I'd love it...especially someone with hardwood pellets, though I don't know if that would really make a difference.
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