koker hook up

Since this forum has slowed down recently, I thought I would post my experience hooking up my koker to the coal-trol for critiquing and possible use in the future as tips for someone else.

To start with, I wired the load side of the high temp limit switch (the red e-wire that is hooked to the upper right, temp limit side of the fan limit switch) into a new outlet box utilizing the existing neutral and ground wires on the stove (stove still needs to be plugged in to provide a path for the neutrals and grounds). This allows the new outlet to totally shut down via the limit switch if the koker overheats. Since I disconnected the limit wire at the junction box (where it was connected to the stoker and idle timer lines), that effectively shut the idle timer down.

Stoker motor – pretty straight forward, it is at the end of the stoker/combustion fan circuit so I just re-wired it to a new plug

Combustion fan - re-wired that to a new plug so the coal-trol would control it. With the coal-trol plugged into the new temp limit controlled outlet, both the stoker AND combustion blower will shut down in an over-heating event. This is actually better than the factory wiring that came with the stove, as only the stoker motor was wired to turn off if the limit switch tripped.

Convection blower – this was another easy wiring job. The conv. blower is on a separate circuit controlled by the fan limit switch so I just disconnected it and wired it to a new plug.

It took me about ½ hour to set it up, but unfortunately I did it while the stove was on idle so my fire went out while I had the stove shut off, so I just had to start the fire again once I was done. All wires that were undone and not used by the coal trol were secured with wire nuts so no wire was left exposed since the stove itself was still plugged in and some of them may still carry a charge.

MIN/MAX – I started with the installation pamphlet’s suggested starting values of 10 and 80, but found them to be way too high. With these settings I had about 2-3” of red coals on idle and burning coal being pushed off the stoker grate at full burn. I reduced the min down to 4 and that gives me a good 1” burn across the entire grate and reduced the max to 45 which gave me 1.5 to 2” of ash, but running with that value the first night, the stove couldn’t keep up with the temp drop in the house. I re-did the max setting and found 55 to leave just shy of an inch worth of ash on the grate. I found the coal trol still lagging behind slightly at that setting so I boosted it to 65 and that seems to help decrease the stove’s response time. I did max the stove out with the 65 setting, and it pushed hot coals off the grate but my federates don’t climb much past 50 (so far) so I am not at risk of pushing hot coals into the bucket under normal heating circumstances, unless my feed rates go way up (will have to keep my eye on it if we actually get some cold temps).

My convection blower was problematic, through no fault of the coal-trol. Due to the nature of the blower (Dayton 1XJX8), it can only be run at a minimum CFM setting of 40, which is pretty much full speed. So, the blower would kick on at a feed rate of 8 (low fire and low bonnet temp) and the stove would really have to work to produce enough heat to overcome the blower constantly washing the bonnet of its heat. I ended up hooking the blower back to the stove’s fan limit switch rather than raising the CFT to better utilize the heat generated at low feed rates.

It has been working very well at maintaining the set temp. I am not using any setbacks and from what I have experienced, set backs are not worth it. Even while making adjustments to tune it in, it took quite a while for the thermostat to settle in. There was no problem with the hardware, the system would just have to go through its learning curve at each change in order to settle in.

So please let me reiterate some words of wisdom: as with other adjustments on coal stoves, once everything is set, don’t FUSS with it, just leave it alone and let it do its thing!!!

Nice. Sometimes it takes a littel configuring to get them tuned up!

Thats basically what we keep telling people about the setups, once you get it "dialed In" just leave it run.!

Not sure which version of coaltrol, but there is an Advanced setting for HLF (Heat Loss Factor) to make it react a bit faster. (Settings of 0,1,2).

Based on what I have read in this forum, I believe the HLF only effects/helps out when you are increasing temperature to a new, higher set point (if you are increasing your house temp in the morning as you wake up).

I have mine on HLF 2, since our house is large and cools down quickly, and the stove is in the basement, so there is a good lag time. It seems to respond a bit better, it ramps the Feed Rate up faster to help maintain the temps more evenly. Mine only runs about 1 degree off when it starts cooling down until it catches up.

If I need a quick heat up. Sometimes, I will just hit the Menu, hold it until FEED appears, hit to display 10, let it feed for 10 mins, it heats up FAST, then kick up the blowers for about 20 mins, it can raise the temp 2-4 degrees pretty quick.!

After working with the coal-trol the past few week, I have found the koker's convection blower works, as advertised, with the coal-trol, but as stated above it runs the blower within a smaller RPM range due to CFM needing to be set at 40 or above.

When I first tried the coal trol, my mind was still in digital (on/off) thermostat mode, so I couldn't wrap my head around how the conv. blower running pretty much all the time could keep enough heat moving as the stove's feed rate lowered after thermostat was satisfied. Keep in mind, this is my first year burning coal also, and it took a while just to get used to the burning characteristics of a solid fuel (long heat up and cool down times).

So, a couple weekends ago I re-hooked my conv. fan back to the coal-trol and forced myself to leave it alone all weekend. What I learned is that, at least during cold weather, the coal trol thermostat doesn't actually get satisfied, in a matter of speaking. In my situation with a CFM of 40 (MIN MAX at 6 and 65, CFT at 10), my stove's feed rate would drop to about 12-14 and hover there, thus keeping the plenum around 90 to 100 F and thus keeping the house's temp from dropping quite so fast (at the reduced blower RPM). When the coal-trol needs to ramp up the feed rate to maintain temp, it would rise up to about a FR 30. So the blower hardly ever shut off, which I believe is how the coal-trol is meant to run it. Similar to what I have read in the past, the coal-trol is best compared to cruise control on a car. You still burn gas (more than at idle) as you are coasting on a level stretch of road, but when you encounter an incline the car's rpm increase to keep you going that same speed. This is exactly what happens with your stove hooked up to a coal-trol.

I was also concerned with the fact that once the FR dropped below 9 or so, the conv. blower would turn off and all the heat generated as the FR fell to 0 wouldn't get blown into the living space (again, in my mind, I was comparing it to an on/off thermostat that drops the feed rate to idle at end of heating cycle). Obviously, in my case, if the feed rate drops and hovers to around 12 or so, the blower will keep pumping the heat upward.

I am pretty sure my coal usage is about the same or better, even with the lowest feed rate hovering around 12. This keeps the feed rate at a more constant value, where before when the blower was hooked to the limit switch, it (FR) would pretty much bounce back and forth between 0 and 30-40.

This coal burning deal is definitely a learning experience, but I am glad I took a few months to learn how to operate the stove manually before going the coal-trol route. I apologize if I steered anyone the wrong way with my starting post concerning the conv. blower. I still think the coal-trol really shines when you are using a smaller conv. blower on a stove that is operating in the living space, thus you are using the full range of RPM's on the blower, but it is working very well with the koker's equipment also.