Everything Drolet Tundra - Heatmax...

[Socratic Monologue]

SBI finally emailed me back with the specs for the blower speed vs plenum temps. Also the safety cut off for plenum temp. Here is what they said.

The blower modulates based on the plenum temperature. If the plenum reaches a temperature of 250 F then the unit will automatically close the air supply damper and put the blower on high (speed 4) until the temperature drops below 175 F. See KIP ( Kick In Point) and KOP (Kick Out Point) values below.

This is really useful info. Thanks!

Is there any other way (such as on the display, without extrapolating from the plenum temp) to tell which speed the blower is running on the T2? Is there any use at all for that display other than viewing the plenum temps? Would be interesting to be able to alter those KIP/KOP values.

I'm leaning toward doing the ICM mod, but I'd like to feel as if I understand what the blower is doing in its stock configuration before I make changes. I guess the difference between speed 1 and speed 2 is so slight I'm not convinced it exists.

 

[Gbawol42]

This is really useful info. Thanks!

Is there any other way (such as on the display, without extrapolating from the plenum temp) to tell which speed the blower is running on the T2? Is there any use at all for that display other than viewing the plenum temps? Would be interesting to be able to alter those KIP/KOP values.

I'm leaning toward doing the ICM mod, but I'd like to feel as if I understand what the blower is doing in its stock configuration before I make changes. I guess the difference between speed 1 and speed 2 is so slight I'm not convinced it exists.

Yes. I was going to begin looking into lowering that KOP on speed one a little lower. Not sure if it's even possible. My biggest thing I believe is i need to out a air return duct on, hoping that can improve temps a bit heading upstairs.

 

[Socratic Monologue]

I have some questions about the ICM blower mod that weren't directly answered in the thread so far:

Is the ICM333 appropriate? (https://www.icmcontrols.com/productdetails/ICM333) Seems like the other ICM models mentioned here, but the 333 has an adjustable temp setpoint (70F-140F), which I assume would do the work of the resistor that some folks have put on their probe. I don't know if there is some other aspect of this controller that makes it different from the ICM 326 that I've seen mentioned.

Is it best to hook line 120vac to the controller, or to run the speed 1 lead from the stock T2 control board?

I need a 24vac transformer to power the ICM, I believe. Is there a reason to somehow switch this power (high temp thermostat?) or just leave the ICM powered all the time?

I installed a thermostatic damper control, but I feel like I understand the basic idea behind the blower mod less well (though I do see a need to catch some of the late-burn heat better). Any and all advice will be appreciated.

 

[brenndatomu]

I have some questions about the ICM blower mod that weren't directly answered in the thread so far:

Is the ICM333 appropriate? (https://www.icmcontrols.com/productdetails/ICM333) Seems like the other ICM models mentioned here, but the 333 has an adjustable temp setpoint (70F-140F), which I assume would do the work of the resistor that some folks have put on their probe. I don't know if there is some other aspect of this controller that makes it different from the ICM 326 that I've seen mentioned.

Is it best to hook line 120vac to the controller, or to run the speed 1 lead from the stock T2 control board?

I need a 24vac transformer to power the ICM, I believe. Is there a reason to somehow switch this power (high temp thermostat?) or just leave the ICM powered all the time?

I installed a thermostatic damper control, but I feel like I understand the basic idea behind the blower mod less well (though I do see a need to catch some of the late-burn heat better). Any and all advice will be appreciated.

The 333 should work...but I think I recall someone tried one and didn't like the way it worked.
I have tried hooking both the hot and the neutral through the ICM...seems to work fine either way...their directions are vague I think...but it appears that they call for the neutral side of the motor to go through the ICM
As far as how to wire it up specifically to a T2...I've never messed with a T2, but @Case1030 did his.
Some people power the ICM all the time...some have wired it in after the factory blower controls. I've done both...currently leaving the ICM do all the controlling. I unplug the power to the furnace and everything in the off season then.
As for the resistor on the temp probe...I have since switched to a 5k pot...easily adjustable to dial in your specific setup.

 

[Mrpelletburner]

Having added the ICM mod before, I not sure it is worth installing an ICM with the newer units as the blower cut off temp seems to be between 105 and 110....

 

[3fordasho]

I have some questions about the ICM blower mod that weren't directly answered in the thread so far:

Is the ICM333 appropriate? (https://www.icmcontrols.com/productdetails/ICM333) Seems like the other ICM models mentioned here, but the 333 has an adjustable temp setpoint (70F-140F), which I assume would do the work of the resistor that some folks have put on their probe. I don't know if there is some other aspect of this controller that makes it different from the ICM 326 that I've seen mentioned.

Is it best to hook line 120vac to the controller, or to run the speed 1 lead from the stock T2 control board?

I need a 24vac transformer to power the ICM, I believe. Is there a reason to somehow switch this power (high temp thermostat?) or just leave the ICM powered all the time?

I installed a thermostatic damper control, but I feel like I understand the basic idea behind the blower mod less well (though I do see a need to catch some of the late-burn heat better). Any and all advice will be appreciated.

Don't know if I got a bad one but my particular ICM333 has a couple characteristics I wasn't happy with - first the hard start didn't work, the hard start should start the fan motor at full voltage for a second or two and then drop the speed to what ever level the thermistor is measuring. Mine started the motor at reduced voltage. The totaline unit bren recommends works correctly and I've tried two of them. 2nd there is a switch over point on these unit when it drops from full voltage to the start of the speed control range, so from 100% (green led on) to ~80% on down (yellow led on) That initial drop is very noticeable and my ICM333 would alternate between the two many times during some burns. sometimes rapidly. Both totaline units I'm using do not do this. The only down side of the totaline unit is there is not temp adjust pot on the unit - easy to solve however, I just added a 10 turn 5k pot in series with the thermistor and it works great!

One more thing both units will run the blower very slowly at the end of the burn, too slowly in my opinion-regardless of setting on the cut out pot- you could barely hear it running. I added an adjustable snap switch to shut down the 24vac to the ICM333 or Totaline unit to shut it down the blower before it could run that slowly.

 

[Socratic Monologue]

Thanks for all the info so far. This helps a lot.

Don't know if I got a bad one but my particular ICM333 has a couple characteristics I wasn't happy with - first the hard start didn't work

There's a report here about an ICM failing, too. I know things die, but maybe the quality of the ICMs in lacking.

Having added the ICM mod before, I not sure it is worth installing an ICM with the newer units as the blower cut off temp seems to be between 105 and 110....

Yes, it cuts out at 110F, but has to rise back to 125F to kick on again. Is the T1 much different in cut out temp?

 

[brenndatomu]

I know things die, but maybe the quality of the ICMs in lacking.

ICM is regarded to be a top quality brand by HVAC people...

 

[Socratic Monologue]

ICM is regarded to be a top quality brand by HVAC people...

That's good to know. It is made in the US, too, so it has that going for it.

Mostly because it seems to be the most well-tested option here and I'm feeling a bit cautious today, I've just ordered a Totaline. I'll report back once I've run it for a while.

 

[sloeffle]

The totaline unit bren recommends works correctly and I've tried two of them. 2nd there is a switch over point on these unit when it drops from full voltage to the start of the speed control range, so from 100% (green led on) to ~80% on down (yellow led on) That initial drop is very noticeable and my ICM333 would alternate between the two many times during some burns. sometimes rapidly.

My old ICM did that too. I have the Totaline now and it doesn't do that like the ICM did. The motor on my furnace also made some very weird noises with the ICM controller too. I bought the ICM controller from eBay so it is hard to tell what life it lived before I bought it too.

There's a report here about an ICM failing, too. I know things die, but maybe the quality of the ICMs in lacking.

My ICM 326 died last winter on a Friday night before a big cold snap was heading this way. I found a local HVAC supply house that would sell one to me but they only sold Totaline. The reason I didn't get the Totaline to begin with was that I had to run a wire back to my 24V transformer. Push came to shove and I picked the Totaline up locally, wired it up and my furnace runs a lot better with it than the ICM controller I had before.

I bought a supposed brand new ICM controller for $20 off eBay last year as a backup. I couldn't find a Totaline any where in that price range on eBay. I think I gave around $150 for the Totaline from the local HVAC company. If the current Totaline were to die I'd use the ICM until I could find a Totaline at a half way decent price or I'd just go buy another Totaline from the local HVAC company. I keep the flebay ICM around because with my luck, the next one will die on a Saturday night and I'd be stuck until Monday. I'm some what of a worry wart, so I have two furnaces, two hot water heaters, two tractors, three vehicles for two people and list goes on.

 

[brenndatomu]

What's weird is that I'm almost positive that ICM makes the Totaline stuff too...

 

[Socratic Monologue]

What's weird is that I'm almost positive that ICM makes the Totaline stuff too...

I read that on an HVAC forum, too.

ICM's website says they have only one US facility, though, and the Totaline controllers are made in China. Totaline is a subsidiary of Carrier; I couldn't find any corporate connection to ICM.

 

[Gearhead660]

The 333 should work...but I think I recall someone tried one and didn't like the way it worked.
I have tried hooking both the hot and the neutral through the ICM...seems to work fine either way...their directions are vague I think...but it appears that they call for the neutral side of the motor to go through the ICM
As far as how to wire it up specifically to a T2...I've never messed with a T2, but @Case1030 did his.
Some people power the ICM all the time...some have wired it in after the factory blower controls. I've done both...currently leaving the ICM do all the controlling. I unplug the power to the furnace and everything in the off season then.
As for the resistor on the temp probe...I have since switched to a 5k pot...easily adjustable to dial in your specific setup.

I am in the process of doing the adjustable speed mod on my T2. Where has the temp probe been installed in the plenum?

 

[brenndatomu]

I am in the process of doing the adjustable speed mod on my T2. Where has the temp probe been installed in the plenum?

I've never run a T2...mine was a 1, and no plenum on it... @Case1030 did his T2...

 

[Case1030]

I am in the process of doing the adjustable speed mod on my T2. Where has the temp probe been installed in the plenum?

I placed the probe in between the plennum extension.

 

[Mrpelletburner]

Do you mind posting a couple more photos of your setup? Is that I timer I see connected?

 

[Gearhead660]

I placed the probe in between the plennum extension.

Thanks. Waiting for all parts to arrive. Will update when i get it up and running.

 

[Case1030]

@Mrpelletburner, here you go... a few cobwebs. I have both a high temp relay and another low temp relay to open during the coaling stage for very cold weather.

 

[Mrpelletburner]

Thanks! I had this setup working great with the FC1500, still on the fence if I am going to add it to the Heatmax. I do plan on adding the timer as that was a great “set and forget” mod.

 

[Gbawol42]

Thanks! I had this setup working great with the FC1500, still on the fence if I am going to add it to the Heatmax. I do plan on adding the timer as that was a great “set and forget” mod.

I would be late for work everyday without the timer mod, should be a standard

 

[Getwidit]

I would be late for work everyday without the timer mod, should be a standard

Anyone have a how to for the timer model? I've had issues with my thermostat. When its wired it opens the damper and wont close even when temp is achieved.. I'm going to try another stat but I'm almost positive nothing wrong with it.

 

[Mrpelletburner]

Yes... just connect the 2 wires from the timer to the 2 post terminals that you also connect the thermostat to.

 

[Case1030]

Anyone have a how to for the timer model? I've had issues with my thermostat. When its wired it opens the damper and wont close even when temp is achieved.. I'm going to try another stat but I'm almost positive nothing wrong with it.

The tstat has to be positioned so far away from the furnace. They have a diagram in the manual.

But honestly the timer mod is the way to go. I'm sure it increases the longevity and efficiency of the furnace aswell.

Later today I'll try to dig up some old posts regarding the timer/temp controller mod.

 

[Gbawol42]

Yes... just connect the 2 wires from the timer to the 2 post terminals that you also connect the thermostat to.

This is how mine is, when the timer is on it's just like the tstat is calling for heat. Timer clicks off, damper closes. Plus I'll never forget to flip the damper switch after reloading.

 

[Getwidit]

The tstat has to be positioned so far away from the furnace. They have a diagram in the manual.

But honestly the timer mod is the way to go. I'm sure it increases the longevity and efficiency of the furnace aswell.

Later today I'll try to dig up some old posts regarding the timer/temp controller mod.

I understand all the clearances. How ever if I set my thermostat to 65, the reading temp says 75 in the room. The damper should be closed... how ever no matter what when the wires are connected from thermostat to unit. Even when I have the thermostat turned off the damper opens and stays open..