Hi, Has anyone measured the differential for the Harman room temperature thermostat?
I have a P68 that I purchased in June 2014.
Based on my measurements, the differential seems to be +3. In effect, three degrees above
the set point. For example, at a room temperature mode setting of 60* (Set point = 60*), the temperature of a
nearby thermometer will range 60* to 63*, as the pellet stove cycles on and off.
In other words, the stove re-ignites and resumes putting out heat at 60* continuing to put out heat
until the room temperature reaches 63* at which time the stove shuts down the fire.
I have located the room temperature probe (that feeds a signal to the stove) about
three feet above and three feet to the left of the stove. I have placed an independent thermometer
three feet above and three feet to the right of the stove, as an independent check on the
the stove. I wanted the independent thermometer to be the same distance from the stove as the temperature
probe that feeds a signal back into the stove. I have measured that the temperature a few feet from the
pellet stove will cycle quite consistently about 3 degrees between the "high" when the stove shuts itself off,
to the "low" temperature when the stove comes back on.
And yes, the further from the the stove, the temperature variation will become a smaller
variation, probably by the distance of the next one or two rooms, the variation will be zero and the next
one or two rooms will be nearly at a constant temperature, despite that the stove is cycling on and off.
If some of this seems confusing, if you do a search on thermostat set point and differential,
reading up on it will be interesting.
I have a P68 that I purchased in June 2014.
Based on my measurements, the differential seems to be +3. In effect, three degrees above
the set point. For example, at a room temperature mode setting of 60* (Set point = 60*), the temperature of a
nearby thermometer will range 60* to 63*, as the pellet stove cycles on and off.
In other words, the stove re-ignites and resumes putting out heat at 60* continuing to put out heat
until the room temperature reaches 63* at which time the stove shuts down the fire.
I have located the room temperature probe (that feeds a signal to the stove) about
three feet above and three feet to the left of the stove. I have placed an independent thermometer
three feet above and three feet to the right of the stove, as an independent check on the
the stove. I wanted the independent thermometer to be the same distance from the stove as the temperature
probe that feeds a signal back into the stove. I have measured that the temperature a few feet from the
pellet stove will cycle quite consistently about 3 degrees between the "high" when the stove shuts itself off,
to the "low" temperature when the stove comes back on.
And yes, the further from the the stove, the temperature variation will become a smaller
variation, probably by the distance of the next one or two rooms, the variation will be zero and the next
one or two rooms will be nearly at a constant temperature, despite that the stove is cycling on and off.
If some of this seems confusing, if you do a search on thermostat set point and differential,
reading up on it will be interesting.
