Temperature Overshoot At Start-up

Temperature Overshoot At Start-up

PostBy: etned On: Fri Oct 21, 2011 10:39 am

Newbie to coal and coal-trol. Thermostat/stove new and was installed recently. Also had thermostat upgraded to the latest firmware at the Coal-trol shop.

I think I am having an issue with temperature overshoot initially after start up. I set the thermostat temp a couple of degrees below ambient room temperature before starting the stove. The stove starts properly but after 45 minutes or so the room temperature has risen at least 10 degrees over the ambient room temperature.

Example: Ambient Room temp was 60, set thermostat temp to 58 before starting, auto temp set was 72, after 45 minutes or so the ambient room temp is 82 with no signs of stove slowing down. The auto set is reading 72 based on pre-set time setting. Fan speed is set for auto. Min is 4 and max is 30. If I manually reduce the thermostat temp by a couple of degrees then the burn settles down and the fan speed reduces significantly and after an hour or so the ambient temperature and the set temperature are very close and everything seems to work well after that.

I am I missing something??
etned
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pocono Rear Vent

Re: Temperature Overshoot At Start-up

PostBy: EarthWindandFire On: Fri Oct 21, 2011 11:10 am

Hi etned,

I just got a Leisure Line coal stove a few weeks ago so burning coal is new to me also!

The temp overshoots are normal, and you will soon figure out how to minimize that. First, by setting your "desired" temp a few degrees below ambient room temperature and second, by leaving the coal-trol locked on MIN until the stove has stabilized.
EarthWindandFire
 
Hot Air Coal Stoker Furnace: Leisure Line Lil' Heater.
Hand Fed Coal Stove: Hitzer model 75.
Other Heating: Oil and Natural Gas.

Re: Temperature Overshoot At Start-up

PostBy: pvolcko On: Fri Oct 21, 2011 1:08 pm

The temperature below ambient trick will work, but if it has been on for a while with a higher than ambient setting that the FR has ridden up. Set it below ambient and leave it for a while (hour or more) before starting it. If you want FR to drop down faster, set setpoint 5 or so below ambient.

Another option is to set setpoint a couple degrees below ambient and then go to the MIN screen in SETUP. This will run the stoker at the minimum rate and also let the control logic wind down the FR in the background. After an hour or two, put the control back into the round robin by exiting the SETUP menu, and it will run from there. Adjust the setpoint where you want it.

Also, it isn't too cold yet, so you may find you need to use a lower MAX setting than you normally do in the winter (try half the default/normal for your stove). This will limit the overshooting you may see on upward setpoint changes.
pvolcko
 

Re: Temperature Overshoot At Start-up

PostBy: etned On: Fri Oct 21, 2011 1:43 pm

Thanks,

That sounds like the fix I need.

Ed
etned
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pocono Rear Vent

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