New Drolet HeatPro update

[dchance]

After install of a new Drolet HeatPro, I came here with questions on draft reading and control. Took the advice on here and have it dialed in I think. I installed a baro damper and also have a Dwyer Mark 2 working. Adjusted draft to be .05 with a hot fire. Should be right where it needs to be. The last 2 days have been the first time heating the house with the new HeatPro. 3500 sq ft. and it is doing great. Way more efficient than the old Powrmatic. Couple more questions however:
1. what is a decent flue temp? my infrared thermo read at around 300 degrees F. I bought Fieldpiece magnetic pitot tubes for my Dwyer and installed it between the stove and baro damper and it got hot enough to melt the rubber tube off. How can I keep this from happening?
2. The temp reading on the rear control board when burning a really hot fire (which I assume wat the plenum temp?) was a high of about 160s bot more steady at 140s. Is this a decent running temp? I have not checked the SP of the plenum.

 

[3fordasho]

My Tundra's cruise about 300-400F internal pipe temp with the inlet damper closed - sometimes higher on a windy day as I don't have a barometric damper. I'm using a probe type thermocouple inside the pipe and a digital temp controller to measure temps so this is not comparable to a external pipe temp reading with a infrared themo so your 300F external temp is much higher inside. As far as the rubber hose melting off I think most people use a length of metal tubing (brass or copper) stuck into the flue pipe leaving enough length on the outside to keep the rubber tubing away from the heat.

 

[brenndatomu]

Your internal pipe temp will be about double the external temp on singlewall pipe. Mine ran in the 300's (internal) most of the time...but I had a temp controller added on too, so...
Is this 300* with the damper open, or closed...it will be a lot higher when its open.
Don't overthink the manometer tube...just get a 18-24" long piece of tubing that the rubber will push onto, bend the tube into an S shape, hang it in the hole in the pipe, done.
The plenum temp sounds higher than what I seen with my Tundra 1, but this is a HP, so maybe not a good comparison...I don't think you are outside the range of what could be called normal...if its too high the blower will kick up the speed. You can check the SP if you want...just make sure its not too high...if its too low, I wouldn't worry about it, unless its not heating your house well...even then, probably something else.

 

[Gearhead660]

I have the smaller T2, after closing damper and settling in, the internal flue temp settles around 300*. The plenum temp peaks around 150-160*. If I leave the damper open too long I have seen plenum temps of 180*. After adding the temp controller, that doesn't happen anymore. Its a modification that's well worth it for ease of use and monitoring flue temp.

 

[dchance]

those temps were with it running hot, damper open, thermo calling for heat. Once house gets to temp and the thermo cycles, everything cools off. damper is always open though. when I closed it the manometer shot up to .08. I adjusted the weight to keep it running at .05.

 

[brenndatomu]

damper is always open though.

That's exactly what the AM temp controller setup was good at "fixing". It was originally thought up to stop the "over-firing" that SBI claimed was making the Tundra 1's crack, (didn't work...the cracking was a design, and maybe a materials issue, a lot more so than any over-firing that went on)(I know of at least one T1 that cracked even with all the updates and a temp controller on it from day 1)
Anyways, the way it works is this, load and light, open the damper using the newly installed bath fan timer in parallel with the factory manual "on-off" switch, the temp controller monitors the internal flue temp via a thermocouple installed in the pipe, when it gets to your preset max temp, it over-rides the call for heat (which could be coming from the T-stat too) until (if) the flue temp falls to a minimum preset temp...it will then allow the damper to re-open IF the call for more heat is still there (timer, or T-stat)
It makes the furnace a "load n go" setup, especially if doing a hot reload, and not a cold start, although it makes that a lot easier too.
It really bumps the efficiency of the furnace up, because when the intake damper is open, the flue temp goes up and the efficiency goes down.
If you do a search here, there is lots of info on doing this...you can click the link in my sig line too, that will get you to the now HUGE Tundra thread, which discusses how to do it...IIRC, this temp controller was the brain child of @3fordasho originally...there are quite a few members here running this setup now too...so questions, shoot. BTW, I believe your HP would be very similar to the wiring on the T2...

 

[dchance]

That's exactly what the AM temp controller setup was good at "fixing". It was originally thought up to stop the "over-firing" that SBI claimed was making the Tundra 1's crack, (didn't work...the cracking was a design, and maybe a materials issue, a lot more so than any over-firing that went on)(I know of at least one T1 that cracked even with all the updates and a temp controller on it from day 1)
Anyways, the way it works is this, load and light, open the damper using the newly installed bath fan timer in parallel with the factory manual "on-off" switch, the temp controller monitors the internal flue temp via a thermocouple installed in the pipe, when it gets to your preset max temp, it over-rides the call for heat (which could be coming from the T-stat too) until (if) the flue temp falls to a minimum preset temp...it will then allow the damper to re-open IF the call for more heat is still there (timer, or T-stat)
It makes the furnace a "load n go" setup, especially if doing a hot reload, and not a cold start, although it makes that a lot easier too.
It really bumps the efficiency of the furnace up, because when the intake damper is open, the flue temp goes up and the efficiency goes down.
If you do a search here, there is lots of info on doing this...you can click the link in my sig line too, that will get you to the now HUGE Tundra thread, which discusses how to do it...IIRC, this temp controller was the brain child of @3fordasho originally...there are quite a few members here running this setup now too...so questions, shoot. BTW, I believe your HP would be very similar to the wiring on the T2...

Looks like I have some more research to do......just when I thought I was all set....LOL

 

[brenndatomu]

Looks like I have some more research to do......just when I thought I was all set....LOL

Meh, if its heating your house and you are happy, no need to mess with it...but, I can guarantee you that you won't be disappointed with the temp controller if you do it...and its fairly cheap/easy too

 

[andym]

Looks like I have some more research to do......just when I thought I was all set....LOL

I have the temp controller installed on my Heatmax2. I would be happy to give you any information you need, but there are others here who are much more knowledgeable. The temp controller is somewhat optional for these newer models. As mentioned though it does increase efficiency, as well as provide peace of mind. It helps to give you a little more control over burn times also.
Your temps sound about right. A huge bonus with the temp controller is being able to see the real time digital flue temp.