Temperature differences in Coaltrol vs. Other Thermometers

Paul/Neil

I have the Coaltrol thermostat above my Digital Furnance Thermostat with a digital Temp/Humidity above them on the wall.

The other 2 digital thermostats have almost the exact same temp, but the CoalTrol reading is normally 2-5 degrees higher?

Can I change the BIAS on it? I did raise the one setting to 140 and it seems to get the temps a bit closer.

Hmm... Just looking at the code now. Looks like the bias adjustment is an inverse setting compared to the temperature readout. Increased TB values will result in lower temp readings, decreased values will result in increased temp readings. So you should have to increase the TB setting to bring the Coal-trol's temp readout into line with your other thermostats. A bias adjustment of 7 will change the temperature reading by 1 degree F.

So, keep going with the bias adjustment to get them to line up better.

I also have 3 thermostats on the same wall. well the honeywell for the boiler the coal-trol and an indoor outdoor thermometer. My coal-trol is usually 90% of the time 3 degrees lower then the other 2 ?
Chris H

Yes, I did go up to 140 for now, it seems a bit closer within a couple, but will bump a bit more to get it in line with my other thermostats. That is what I was thinking after experimenting with the values and saw which way it was going when I went lower on the TB.

Thanks for the quick response.!!!

choyt002 wrote:I also have 3 thermostats on the same wall. well the honeywell for the boiler the coal-trol and an indoor outdoor thermometer. My coal-trol is usually 90% of the time 3 degrees lower then the other 2 ?
Chris H

You would need to adjust the bias (TB) lower by 21 or so in order to get them to line up.

Paul, are you able to do that only in the new version ? Id like to be able to adjust mine, as it seems to be 2 degrees lower than my other thermometers. I run the TS2. Thanks.

I will check mine tonight.

Yes, Should be able to, hold button for 15 secs of or until FEED shows, then scroll thru the ADVANCED setup.

Reference

V3 firmware features

I do not believe or at least I do not see that this option of adjustment is available on the ts 2. I just looked and could not find it. Thanks
Chris H

It might a new version of Software in the TS2, when you power it up, is yours Ver. 3?

It was all messed up today, I dropped it down to 120 and the temp said 70, but the others were 64.

So, I bumped it up to 150 and now they all read exactly the same temperature.

You have to hold the Setup button for 15 seconds, then tap it to get the advanced menu.

once I hold it for 15 sec. I get feed then i tap it and get IGNITE, BRNOUT,TEST then back to temp and round robbin guess i don't have it
Chris H

It has v2 021 Bought the stove new a few months ago
Chris H

Older version, I think is has to say V3 064 or something. Those are some of the new features.

V2 021 should have this temp bias available on it. It was introduced late in the V2 series.

Keep holding it past the FEED screen. If you hold it for more than 30 seconds without it changing to a screen like "R ##F" then it isn't on your software version.

Paul, when you go past that bias menu to the next menu it displays "SFN 15" what is that?

I set mine up to 150 a couple days ago and it's holding almost perfect with the other 2 thermometers.....that worked!

Thanks Paul for the great product and service.