CB Users Question - How long does it take to bring water up 10 degrees

Bob Lentz · December 02, 2019, 12:28:57 PM

Just curious, How long under normal load does it take your CB unit to bring the water temp back to the set point once the differential has been met?

Under normal load, it can take 35 to 40 minutes to bring my water up 10 degrees - this seems like a long time. What i have noticed is that it takes a long time to get the reaction chamber up over 1000 degrees.

woody_88 · December 03, 2019, 06:04:44 AM

According to my firestar history, about 15 mins. That's with standing dead elm (almost/kinda punky) and 30 degree outside temp.

I have a classic edge 550

Also I looked at the last 8 hours history and it's about the same. Sometimes 10 mins, mostly closer to 15 though.

Bob Lentz · December 03, 2019, 11:01:58 AM

15 minutes seems right to me - what i cant figure out is why it takes so long to bring the water temps up. Maybe i need to do a more thorough job of cleaning the heat exchanger? Not sure what else i can do - how do you clean your heat exchanger?

woody_88 · December 03, 2019, 11:15:34 AM

Honestly I believe with better tools mine could be cleaner, also I could burn dryer wood. All I use is the supplied firebox stick, the one with the handle on one end (2 piece deal) and the "foot" on the other. I will stick each end in between the fins at the back of the reaction chamber. Trying to wiggle and scoop as much as possible. Sliding it up and down etc...

I will take a picture of some information central sent me recently, regarding the air intake solenoids and their adjustment. Maybe yours are out of spec and are causing slow heat up times.

Bob Lentz · December 03, 2019, 01:23:16 PM

Thanks! - my boiler is new and it has stepper motors, not the old solenoids. In the past the solenoids were binary - open or closed - nothing in between. The new stepper motors adjust the amount of gap - not sure how to test this. I would think that if i had an air intake blockage, it would never get above 1000 degrees - (this has happened to me in the past - blockage)

One of the problems with the new rear access is the insulation sticks to the heat exchanger. After opening the door many times, i don't have much insulation left! wondering if that could be part of my problem in that the rear door is not insulated anymore (very little) and the cold temp of the door is causing the heat excahanger to work harder?

No clue.

woody_88 · December 03, 2019, 01:52:08 PM

You might be onto something with that rear door. Can you replace the insulation on it? Any chance you have access to thermal imaging equipment?? Lol

boilerman101 · December 03, 2019, 11:38:03 PM

My Edge 750HD usually takes between 25-30 minutes to reach the set point during a burn cycle, so Bob's does not sound that unusual. I've found different varieties of wood, wood moisture, outdoor temperatures and coalbed can all can affect the recovery time of a burn cycle. I think the key to good burning is when furnace reaction chamber temp reaches 1,000+ degrees during burn cycles.

E Yoder · December 04, 2019, 07:29:28 AM

Are we talking about reaching temp with a call for heat in the house or with no load? There's potentially a very big difference.

Bob Lentz · December 04, 2019, 08:45:20 AM

I am looking at under load. I have had cycles where it takes 1-2 hours! My unit spends a lot of time in the 750 to 900 degree range. I burn seasoned pinion.

Logging logginglogging · December 04, 2019, 09:13:15 AM

Boiler size, wood, moisture, weather, these are all factors. I use the same cleaning rod mentioned above, and pull the light ash out from between the clots in the reaction chamber when cleaning, then shake the chains and do it again. Lucky for my its very light clean ash. I wonder if the stepper motors are the problem, I wonder if by "regulating" so closely and not being binary if thats why you don't get a good hot burn like mine do at wide open? Kind of like the stupid emissions stuff on newer cars and how they cause all sorts of issues.

woody_88 · December 04, 2019, 10:13:26 AM

Any chance you have firestar XP for diagnostics? I have a pic below from the manual about diagnosing different problems.

Bob Lentz · December 04, 2019, 12:02:42 PM

i have XP installed - i use this religiously to monitor the "health" of he boiler.
One can drive themselves crazy looking at the numbers.

I do have a FLIR device and a digital temp sensor, but have not used that on the rear door - i guess shooting the door from the outside will tell a lot - if the door is hot to warm on the outside, then the insulation is not doing it's job.

woody_88 · December 04, 2019, 01:32:20 PM

Cool! Yes XP is very good with all the information.

I am anxious to hear back with the thermal vision...does it take pictures??

woody_88 · December 07, 2019, 11:50:21 AM

I'll take your times today Bob, this is what I found on my chart this morning...

...get to play detective when I get home...

itzallbtu · December 09, 2019, 05:20:23 PM

Here's a log of one of my recent sequences:

190230 Reaches 186 on normal burn shuts down
185624 Temp 182, high burn shuts down
183255 Temp 175, high burn kicks in
183056 Temp dropped to 175, normal burn kicks in

Fuel is dry red oak, outside temp in the 20's. This is fairly representative of most runs unless I interrupt to load. Furnace is e2300 heating ~2200sf home and 600sf pole barn (insulated better than the house ;))