VC Defiant 1975 Cat C burn issues

[Rusticontheridge]

The digital temp pho to is when it started running away while completely shut down. Air intake on back is shut, cat air intake is half plugged.
Magnetic thermo is totally out of control with the digital within a 30° lower reading.
We did notice air draw it the photo circled under the air intake on the back, Don’t know what it is. Fire picture is raging with the almost 900°reading. but no way to shut it down further.

The fire is one of the first times we burnt it.
Similar fire as the hot fire.
Magnetic is on the stove behind the griddle butted near to the flue base.
Wood is gone within 2 hours
Burning seasoned ash, maple & hackberry mixed.
What is the small hole in the rear below air intake?
It was drawing air

 

[Woodsplitter67]

The thermometer and readings are taken on the griddle.. I use the center and the back of the griddle your measuring more exhaust temperatures then firebox that way

 

[Woodsplitter67]

Set it up like this

 

[Turbo89]

That’s an important clarification, 900 degree CAT temp with it turned way down is a lot different than griddle temp!

The CATS want to run hot, 900 is a nothing burger. With the stove turned down that’s pretty normal. The CAT is active above 600, ideal Range ~ 1,000-1,300 and max around 1650 (this max is often debated here).

In my experience griddle temp seems to lag a little, so if you just turned it down it will take a while to cool off. I think VC lists 650 as max griddle temp, but I wouldn’t be worried about running a little hotter for a while… heck those magnet gauges can be off by 50 degrees.

 

[Woodsplitter67]

I'm saying this jokingly.. if you move your thermometer.. you'll have fixed your stove.

 

[Burnin Since 1989]

I'm saying this jokingly.. if you move your thermometer.. you'll have fixed your stove.

The only thing is, he's going through wood really fast. I think there is still some sort of issue. Shouldn't he be seeing 6-8 hours at least, on a load?

What is the small hole in the rear below air intake?
It was drawing air

Good question if it's pulling air? One of the guys more familiar with your stove should be able to answer that

 

[Woodsplitter67]

The only thing is, he's going through wood really fast. I think there is still some sort of issue. Shouldn't he be seeing 6-8 hours at least, on a load?

No not necessarily. 6/8 hours depending on how the primary air is set and species of wood is correct. Also how much is in the box has a ton of play in it to.

 

[Rusticontheridge]

Set it up like this

What is a normal griddle temp on a proper
Burn?

That’s an important clarification, 900 degree CAT temp with it turned way down is a lot different than griddle temp!

The CATS want to run hot, 900 is a nothing burger. With the stove turned down that’s pretty normal. The CAT is active above 600, ideal Range ~ 1,000-1,300 and max around 1650 (this max is often debated here).

In my experience griddle temp seems to lag a little, so if you just turned it down it will take a while to cool off. I think VC lists 650 as max griddle temp, but I wouldn’t be worried about running a little hotter for a while… heck those magnet gauges can be off by 50 degrees.

900° was the stove top temp at the base of stove at the flue pipe.
Going to move it to the griddle

 

[Rusticontheridge]

The only thing is, he's going through wood really fast. I think there is still some sort of issue. Shouldn't he be seeing 6-8 hours at least, on a load?



Good question if it's pulling air? One of the guys more familiar with your stove should be able to answer that

We are getting a 2 hour max burn.
Problem is we can’t shut it down if it gets going too hot.

 

[Woodsplitter67]

What is a normal griddle temp on a proper
Burn?

900° was the stove top temp at the base of stove at the flue pipe.
Going to move it to the griddle

This depends on how your stove is set up. There is no real here is your temperature.

This mornings burn was like this

Getting the stove up to temperature SST650
Getting the cat going around SST 600
Cat going top was about 500 with air cut half way back
I cut the air all the way back and the SST dropped to like 430

 

[Rusticontheridge]

I'm saying this jokingly.. if you move your thermometer.. you'll have fixed your stove.

We are burning seasoned ash, maple & hackberry. Can’t put more than 3-4 logs in there because it runs like an inferno even though the air intake is closed, & cat intake is shut down. It runs the same with no way to shut the fire down. And is completely gone in 2 hours
We’ve burned Quadrafires, & Harman with no issue.
New VC is sitting in the same place as the Harman with the same flue pipe.

 

[Woodsplitter67]

We are getting a 2 hour max burn.
Problem is we can’t shut it down if it gets going too hot.

Most likely it's not getting to hot. Your measuring the temp in the wrong spot.. the picture you posted tell a completely different story of what's actually happening. I'm pretty sure it's running correctly.

Take a breath.. move the thermostat and run the stove, take some pictures and note the SST, post back what's going on. We're going to do things 1 at a time and not panic.

 

[Rusticontheridge]

Most likely it's not getting to hot. Your measuring the temp in the wrong spot.. the picture you posted tell a completely different story of what's actually happening. I'm pretty sure it's running correctly.

Take a breath.. move the thermostat and run the stove, take some pictures and note the SST, post back what's going on. We're going to do things 1 at a time and not panic.

We moved magnetic therm to the griddle & gonna see what happens