Princess 32 potential for over firing

[Murray01]

Now that winter is here, -30C to -40C nighttime temperatures I’m running my new Princess hard. Wondering if I’m running the risk of long term damage.

Hot reload I put the thermostat dial at 6:00, fully open. CAT thermometer about 12:00-2:00 position. Reload the stove, close bypass and let it run on fully open for 20 minutes, after 20 minutes I’ll dial the thermostat to about the 5:00-4:30 position and that’s where it stays for 3-4 hours. The CAT thermometer will climb to pinned(6:30 position) and stay there for 3 hours or so.

Can I run the stove on 7/8 wide open for extended periods?

Flames are constantly “licking” the CAT, reading on this forum that’s not ideal. Am I hurting the CAT?

Hot reload CAT thermometer is at the 12:00-2:00 position. I reload as fast as I can to minimize cold air intake. Is there a risk of thermal shock?

In these conditions I’m getting 8 hours burn, stove fully loaded, 15% MS Jack Pine. With normal winter conditions usually get 12-14 hours burn time.

 

[Dieselhead]

How are the flames? Kinda lazy or going wild? How tall is your chimney? As far as hot reload procedure I don’t see anything wrong with the way you’re doing it.

 

[stoveliker]

Remember that you may be putting the Tstat at 5, but the air inlet will close when it gets hotter than "5".
If that works and you don't have too much draft (see flue height above), then that should prevent overfiring.

I think ceramic cats are more susceptible to impingement damage than steel cats.
I have not heard of cats in BKs that were damaged if treated within the recommended parameters.

We used to have a guy here from AK that ran his bk at similar reload schedules, and he didn't have issues.

 

[Murray01]

How are the flames? Kinda lazy or going wild? How tall is your chimney? As far as hot reload procedure I don’t see anything wrong with the way you’re doing it.

Flames are lazy, certainly not wild like a fresh hot reload. Constant flame for the first 4 hours, sometimes it appears they originate from the CAT but mostly off the fuel.

Chimney from stove top to rain cap 13.5’, double wall off the stove.

 

[stoveliker]

Then I think you're not going to damage the stove or cat.

 

[Dieselhead]

Then I think you're not going to damage the stove or cat.

2nd

 

[Murray01]

Remember that you may be putting the Tstat at 5, but the air inlet will close when it gets hotter than "5".
If that works and you don't have too much draft (see flue height above), then that should prevent overfiring.

I think ceramic cats are more susceptible to impingement damage than steel cats.
I have not heard of cats in BKs that were damaged if treated within the recommended parameters.

We used to have a guy here from AK that ran his bk at similar reload schedules, and he didn't have issues.

I can hear the thermostat “click” when I dial the “throttle” down, I running well before the thermostat closes.

I never paid attention to what type of CAT I had before installing, it stove sat in our garage for 5 months in its original crate till installation, I did look at it once we uncrated it, my first impression was rust. The honeycomb appeared to have rust on it which didn’t make sense since I thought they were ceramic or precious metal.

My concern is thermal shock but if I wait till the CAT cools down to the recommended/suggested 10:00 position for a reload there wouldn’t be any coals remaining. Shoulder season no problems waiting, cold snap…can’t wait.

 

[Murray01]

Thank you gentlemen for your replies. Between the owners manual and reading this forum I figured I was on the right track. A person gets conditioned to black box mode until it’s pushed. Glass is clean!

 

[stoveliker]

I can hear the thermostat “click” when I dial the “throttle” down, I running well before the thermostat closes.

I never paid attention to what type of CAT I had before installing, it stove sat in our garage for 5 months in its original crate till installation, I did look at it once we uncrated it, my first impression was rust. The honeycomb appeared to have rust on it which didn’t make sense since I thought they were ceramic or precious metal.

My concern is thermal shock but if I wait till the CAT cools down to the recommended/suggested 10:00 position for a reload there wouldn’t be any coals remaining. Shoulder season no problems waiting, cold snap…can’t wait.

When the Tstat clicks upon dialing down depends on the temperature when you dial down. No fixed point. If it's hot, it'll click sooner than when the stove is cold (er).
The click is the air flapper closing. Regardless of where the Tstat dial position is.

If your cat has square holes it's a ceramic one.
Other (and smaller) holes is metal.
But that's just the substrate; there's an oxide wash coat on it in top of which are Pd/Ru/Pt noble metal particles (atomic scale size, forgot the exact elements on these cats).
It is the ceramic substrate that is a bit more fragile than the metal one.

Thermal shock: open the bypass for a few minutes before you open the door as you do. You should be good.

Also avoid at all cost putting in wood that's wet (remnant snow or so on the surface) or not dried enough. Water will evaporate, and to do that take up much energy, so the vapors then are really cool, and that is the worst you can do to a cat.

 

[Murray01]

When the Tstat clicks upon dialing down depends on the temperature when you dial down. No fixed point. If it's hot, it'll click sooner than when the stove is cold (er).
The click is the air flapper closing. Regardless of where the Tstat dial position is.

If your cat has square holes it's a ceramic one.
Other (and smaller) holes is metal.
But that's just the substrate; there's an oxide wash coat on it in top of which are Pd/Ru/Pt noble metal particles (atomic scale size, forgot the exact elements on these cats).
It is the ceramic substrate that is a bit more fragile than the metal one.

Thermal shock: open the bypass for a few minutes before you open the door as you do. You should be good.

Also avoid at all cost putting in wood that's wet (remnant snow or so on the surface) or not dried enough. Water will evaporate, and to do that take up much energy, so the vapors then are really cool, and that is the worst you can do to a cat.

Wood sits in the house for 8 hours or more prior to loading in the stove plus it’s covered.

Thanks for the info on the CAT, sun was shining in today so I was able to turn it down for a couple of hours. Calling for -30C tonight so I’ll check once I reload, it will be glowing!

 

[Burnin Since 1991]

Flames are lazy, certainly not wild like a fresh hot reload. Constant flame for the first 4 hours, sometimes it appears they originate from the CAT but mostly off the fuel.

Chimney from stove top to rain cap 13.5’, double wall off the stove.

BK Manual says minimum 15 foot chimney at sea level not including bends in pipe. What kind of chimney are you using? Class A, insulated liner...

Any bends or straight up? Check google for your exact elevation too. We can figure out what you need

 

[Murray01]

BK Manual says minimum 15 foot chimney at sea level not including bends in pipe. What kind of chimney are you using? Class A, insulated liner...

Any bends or straight up? Check google for your exact elevation too. We can figure out what you need

I’m a little shy on chimney height, that I know. My FIL had a BK Princess (1995) with a 7” flue collar/single wall stove pipe reduced down to a 6” at the ceiling support box in the same location and minimal issues with draft. The WETT Inspector didn’t like that plus a few other issues so we changed everything to meet code.

No bends, 6” doubled wall stovepipe into Class A 6” chimney. Elevation 485m(1590’) above sea level

 

[Burnin Since 1991]

I’m a little shy on chimney height, that I know. My FIL had a BK Princess (1995) with a 7” flue collar/single wall stove pipe reduced down to a 6” at the ceiling support box in the same location and minimal issues with draft. The WETT Inspector didn’t like that plus a few other issues so we changed everything to meet code.

No bends, 6” doubled wall stovepipe into Class A 6” chimney. Elevation 485m(1590’) above sea level

You're supposed to install your stove and chimney etc to the manufacturers specifications. BK Minimum chimney height for your elevation is 15.5 feet. Add a 3 foot section and you will be in compliance. If you run a short chimney, outside of BK recommendations and something happens, then BK may not honor your warranty.

And 13.5 feet of chimney meets code?

 

[stoveliker]

I'd be hesitant adding height given where he is. If it works now, it works.
A 15 ft chimney might get him too much draft in the cold of Saskatchewan winter, and that would thus deteriorate performance and safety.
At 13.5 ft, he does need to be careful for cat stalls in shoulder seasons.

 

[Murray01]

You're supposed to install your stove and chimney etc to the manufacturers specifications. BK Minimum chimney height for your elevation is 15.5 feet. Add a 3 foot section and you will be in compliance. If you run a short chimney, outside of BK recommendations and something happens, then BK may not honor your warranty.

And 13.5 feet of chimney meets code?

Those are recommendations and guidelines, the inspector pointed that out to me.
Meets code.

 

[Highbeam]

You're supposed to install your stove and chimney etc to the manufacturers specifications. BK Minimum chimney height for your elevation is 15.5 feet. Add a 3 foot section and you will be in compliance. If you run a short chimney, outside of BK recommendations and something happens, then BK may not honor your warranty.

=

Yes, that 15' is newly recommended and not required. In 2012 BK only recommended 12' in the manual and that's all I have. Works great.

 

[Murray01]

I'd be hesitant adding height given where he is. If it works now, it works.
A 15 ft chimney might get him too much draft in the cold of Saskatchewan winter, and that would thus deteriorate performance and safety.
At 13.5 ft, he does need to be careful for cat stalls in shoulder seasons.

Never had an issue with CAT stalls, small hot fires and I’ve always stayed within BK “Tested Low Burn Setting”.