Coal trol FR dips below MIN setting and soars above MAX.

Hi everybody. New coal guy here in Upstate NY. I have a question for anyone who can help...we just fired up our Hyfire 2 with a coal trol therm. we have the FR set to MIN 6 Max 40. Today when we over shot our desired temp by a few degrees we we watched in horror as the FR dipped from 99 all the way to 0. We did not lose our fire, however after pouring over the manual for the Coal trol I am confused by this dip since I thought that the MIN and MAX would be the highest and lowest that it would go. Did we overide the MIN MAX settings of 6 and 40 some how? Any clues would help. we love the Coal Trol and the stove so far, and are just abit confused by this one.

thanks!

Welcome to the forum a lot of good info on here. I am new to the coal trol also, I believe the FR means current feed rate,no call for heat ,FR will read 0. I do not know if your min setting works by time when there is no call for heat.

Nope, Feed Rate depends on the demand for heat and the settings. I believe the MIN/MAX are a percent. if you are running at MAX FR99, and you don't have a full grate of coal, (about 1" of ash), then you have to raise the max a couple points. You don't want hot coals falling off the grate, that is too high MAX setting.

It also depends on your location of your thermostat, how far away from the heat source is it? The farther away, the longer it will take to satisfy the setpoint. Also, don't change the temp by too many degrees, 2-3 at the most, otherwise, it runs better if set at a certain temp and leave it there. Otherwise, you can have larger temp swings when it really starts cranking.

COAL takes time to react, it may take an hour or more to come up to temp, if the coal trol can't satisfy the temp within a certain period of time, it will keep increasing the Feed Rate to satisfy the temp, it will continue to raise the FR until the temp is attained. It's not like gas furnance, that is almost instant. Therefore, you have a full grate of coals burning, then the thremostat is satisfied, therefore, it overshoots the temp, dropping the feed rate to stop feeding...then cools down, and starts the cycle all over again, this can take a couple hours for it to finally settle down....

You sometimes have to "Dial IN" your settings, once you figure out how it works and how much your house heats up and cools down.

I think mine is at 8 and 46. Every stove is a little different, they give you the starting point settings that get it close.

I think if I remember, FR is your current feed rate. For example if you have your min is 6 and your max is 40, that is your feed rate scale based on a 100%. So your feed rate is linear after that so essentially 6 is 0% and 40 is 100% and then the coal trol modulates in between there.

Did you have both burners going with an 1or so inches of ash at the end of the burn grate? that must of been cranking some serious heat

I think the overshoots from what I've read are mainly because the thermostat does not have a clear air path to sense the heat. Maybe try the tstat in a differant location.
Have a great day, Eric

Thanks guys. I guess it just took a bit of getting used to. Can't say I really get the percentages thing, but I see how it is working out as we are on day three. The temp has really regulated nicely. We are at 70 and it has hung right around 70 with a FR of anywhere from 8-12 most times that I check. Our coal usage has finally leveled out as we used like 3 bags in the first 36 hrs! (trying to heat a large area from 56 -72deg) Thanks again!

Josh

Hi newHYFIRE2guy, here's the run down on FR, MIN and MAX:

FR is the feedrate and will be anything between 0 and 99 depending on demand for heat. It the percentage of range specified by the MIN and MAX settings.
MIN is the minimum feed setting. It is a value from 1 to 15 (default 6 for LL stoves).
MAX is the maximum feed setting. It is a value from MIN up to 99 (default 40 for LL stoves).

MIN and MAX are both indications of the number of seconds of "on" time the stoker motor will be run for every 100 seconds. So, MIN of 6 means when the control is at idle (FR = 0) the stoker will be on for 6 seconds out of every 100. MAX of 40 means when maximum heat is being called for (FR = 99) the stoker will be on for 40 out of every 100 seconds.

If FR is something in between, say 37, then the stoker will be on for 37% of the on time range specified by MIN and MAX. Using default MIN and MAX, a FR of 37 would mean .37 x (40 - 6) + 6 = 18 seconds of on time per 100 seconds (we ignore fractions, we do not round up).

Thanks Paul,

that helps. I have spent the past few days insulating and trying to figure my house/situation out as I know everyones is different. Getting the heat where you want it to go is not for the faint of heart! Understanding the FR and how to use the coal trol to my advantage sure helps.

thanks again, Josh

We have our Min at 3 and our Max at 32. If we go higher than 32, we lose burning coals off the grate and into the ash pan. Max 32 works well for us, with either one burner or both burners of our Hyfire II running. And yes, getting the heat where you want it isn't for faint of heart, LOL! This is year 2 for us with coal and our Hyfire II. We thought we had it sorted last year, but turns out we didn't. One thing seems to be a malfunctioning Coal-Trol, which began at the end of last year's heating season. The other thing seems to be a bad location where my husband tied the Hyfire into our existing duct work. These things aside, once you get it nailed, you will love that Hyfire and the Coal-Trol, and the customer help from the Coal-Trol guys and LL is tops! Also tops are the members of this forum, without them we'd still be scratching our heads and probably using the propane!

pvolcko wrote:Hi newHYFIRE2guy, here's the run down on FR, MIN and MAX:

FR is the feedrate and will be anything between 0 and 99 depending on demand for heat. It the percentage of range specified by the MIN and MAX settings.
MIN is the minimum feed setting. It is a value from 1 to 15 (default 6 for LL stoves).
MAX is the maximum feed setting. It is a value from MIN up to 99 (default 40 for LL stoves).

MIN and MAX are both indications of the number of seconds of "on" time the stoker motor will be run for every 100 seconds. So, MIN of 6 means when the control is at idle (FR = 0) the stoker will be on for 6 seconds out of every 100. MAX of 40 means when maximum heat is being called for (FR = 99) the stoker will be on for 40 out of every 100 seconds.

If FR is something in between, say 37, then the stoker will be on for 37% of the on time range specified by MIN and MAX. Using default MIN and MAX, a FR of 37 would mean .37 x (40 - 6) + 6 = 18 seconds of on time per 100 seconds (we ignore fractions, we do not round up).

Hey Paul . Mind if I use this on the tip and tricks section on our section ?

Fine with me, although upon reviewing the code, I believe the time base was changed in the V3 code to 120 seconds, not 100 seconds. So the MIN and MAX are percentages of 120 seconds.

MIN of 6 means ON time of 7 seconds and OFF time of 112 seconds. etc.