Block Off Plate Causing Overfire?

[nhburnguy]

Hello All.

I just installed a block off plate over my Timberwolf EPI22 insert using a piece of galvanized duct work. (It was the only material I could find anywhere.)
I'm doing everything the same with the stove as I always have, same fuel, but now my thermometer is getting up to the 700-750F range on a full load instead of the 600-650F range that I regularly got it up to before. I have an IR gun coming in the mail next week so I can check to see if it is the thermometer malfunctioning.
Has anyone else had this experience after installing the block off? I'm thinking that getting the stove up to 750F on each reload is not going to be good for it in the long run. The stove has never started glowing and it doesn't feel hotter when standing close to it. The temperatures in the house are the same as they have always been as well.

Anyone have any advice or experiences they can relate to this?
Thanks in advance!

Nick

 

[jatoxico]

Unless you cannot control the stove I'm inclined to say congratulations, your block off plate is working and you can now get more heat and/or use less wood. Always nice if you can post a pic as these are worth a thousand words or so I've heard.

 

[Sconnie Burner]

I would imagine kinda like shutting the damper in the stove you have reduced the air escaping from around the stove area creating more heat to stay in that area. In effect it keeps everything warmer. Less wood in the stove or closing it down faster should cure the higher temps!

 

[nhburnguy]

Thanks for the replies! The problem is, as soon as I have secondaries, the temp skyrockets to about 750F. If I don't let the secondaries kick in, the flames will die out and it will start to smolder and produce a lot of smoke. I would use less wood, but I need to have those overnight and 8 hour burns to make it worth it for me to heat with wood.
Kind of stuck on what do do about it without removing the plate.

 

[jatoxico]

Unless there is something wrong with how it was installed you're fine. In fact your manual calls for a block off. My block off plate raised my stove top temps too, it's a good thing. What you are experiencing now is just a learning curve. Starter questions;

How long have you had the insert?
Do you shut down the primary slowly as the fire establishes itself and stove temp rises or all at once?
Is it an inside or outside chimney, liner size and total length?
How long ago was the wood split?

A firework show of secondary burning isn't necessarily what you want to go for. To control your burn you should start shutting down primary air in increments, letting the fire reestablish for a few minutes each time and, as was said above, may need to begin sooner than your were used to.

 

[nhburnguy]

I think you might be right about shutting it down more incrementally. I tend to shut it down in two stages but I might have to do it a little less at a time.
This is my second year with the stove. Inside chimney in the center of my house. Wood was split 2 years ago and all of it reads less than 20% with MM.

Thanks for the advice @jatoxico, it is much appreciated!

 

[ailanthus]

Unless you cannot control the stove I'm inclined to say congratulations, your block off plate is working and you can now get more heat and/or use less wood. Always nice if you can post a pic as these are worth a thousand words or so I've heard.

Yep, congratulations, get a fan to help keep the temps down if you don't already have one & enjoy the heat.

 

[jatoxico]

I think you might be right about shutting it down more incrementally. I tend to shut it down in two stages but I might have to do it a little less at a time.
This is my second year with the stove. Inside chimney in the center of my house. Wood was split 2 years ago and all of it reads less than 20% with MM.

Thanks for the advice @jatoxico, it is much appreciated!

Yeah, you probably just have to get used to a new normal. The only reason I asked about chimney length too was because I was wondering if you have an excessively long chimney that could be over drafting making it tough for you to control the burn.

One other thing to double check, I notice your insert manual references an ash dump, right? Doubt you really have one (prob just generic statement about their product line) but if there is, make sure it's solidly closed and sealing good. Any source of uncontrolled air is a potential problem so double check your door gasket too.

 

[nhburnguy]

No ash dump on the insert. The blower attaches right to the bottom of the stove.

 

[branchburner]

I'm thinking that getting the stove up to 750F on each reload is not going to be good for it in the long run.

I'm assuming that 750f is not for an extended period, and that your cruising temps are lower? I would have no worries about 750F if it is not held for hours on end. Glowing means you are at 900+, so you are a long way from a serious overfire.

As mentioned above, a fan will help transfer heat off the stove. I have a fan blowing into one side of the hearth, and that side of the stove runs about 100 degrees cooler than the other, when the fan is on. The fan will help transfer your newly-found heat into the room, whereas some of it used to get directed up into the chimney space.

 

[lml999]

Max observed temp on my insert didn't change at all after I installed a blocking plate. Just getting more usable heat into the room!

 

[begreen]

A blower should bring the temps down 100-150 degrees.

 

[nhburnguy]

I think I was letting the stove run wide open for too long. I just closed it down more incrementally on the last cycle and it didn't top out as hot as before.
Branchburner: it was at 750 for maybe an hour at a time. I don't know if this is ok, but I didn't think it was good for a stove to get that hot regularly. I don't want to warp the top or door!!
This is why this forum is great! Ask a question, get a solution. Thanks!

 

[jatoxico]

I think I was letting the stove run wide open for too long. I just closed it down more incrementally on the last cycle and it didn't top out as hot as before.
Branchburner: it was at 750 for maybe an hour at a time. I don't know if this is ok, but I didn't think it was good for a stove to get that hot regularly. I don't want to warp the top or door!!
This is why this forum is great! Ask a question, get a solution. Thanks!

750 is gettin' there IMO, but I hit that temp a couple times a year at peak. So long as you can control the burn and the choice to hit those temps is yours then you're fine. I let it run up on occasion.

My block off plate raised my cruising temp by about the same as yours, 100-150 for a given load of wood. Holds the heat better and the box (glass and bricks) stays cleaner.

 

[etiger2007]

I live at 750 , grab a beer n enjoy

 

[nhburnguy]

I do notice the heat flowing out of the fireplace more freely when the blower is off.

Etiger: you get it to 750 daily? I must just be a worrier. Is it really no problem until it starts glowing?

 

[brenndatomu]

Steel starts (barely) to glow at 900* or so, more noticeable over 1000*. You have to be well up over 2000* to be "forgeable" (or just starting to be hot enough to soften a bit, enough to be able "work" it) It still takes considerable force at these temps, you gotta go another 7-800* to get to "melting" temps (for carbon steel, which is most steel stoves)
As someone who does a fair amount of metal fab work I can tell you that a steel stove will take 750* ALL DAY LONG without so much as a hiccup. Like Etiger said, grab a beverage and enjoy!

 

[branchburner]

Is it really no problem until it starts glowing?

I wouldn't say "no" problem. Some stoves that run excessively hot, but short of glowing, may show premature damage to bricks, refractory components, gaskets, etc. There have been some Harman users, for example, posting that several of their cast bricks had cracked within the first two years of use, which is premature wear. I could be wrong, but I'd attribute that at least partially to running the stove too hot for too long.

That said, I don't see 750f for an hour as any problem at all.

 

[etiger2007]

I do notice the heat flowing out of the fireplace more freely when the blower is off.

Etiger: you get it to 750 daily? I must just be a worrier. Is it really no problem until it starts glowing?

750 is no issue with my stove. I do get there daily, I had a stove glow on me once and it was scary. My therm measures up to 900 and the needle was pegged. Manufacture replaced my entire stove and Ive never been able to get it passed 800.