Jotul F500 v3 Surface Temp

[bladeofanduril]

I've run 5 or 6 real burns in the stove now. It's performing well and heats the house as hoped (40-50f outside temps).

One thing I'm noticing is that the surface temperature (as measured with magnetic thermometer at left rear corner of stove top) has a hard time getting up to 500F, and I've not noticed it getting any higher than that ever so far. The combuster can be humming along at 1100-1200F with a nice 3-log burn going. Is that normal for the surface temp? Thanks

 

[begreen]

Is this temperature reading with a full load of wood? The catalyst is where most of the heat is located. What does it read directly over the cat?

 

[bladeofanduril]

Is this temperature reading with a full load of wood? The catalyst is where most of the heat is located. What does it read directly over the cat?

I guess it depends on what we're calling a full load. The manual recommends a three-log fire, so this is with three 4-6" thick splits of ash. I'll have to measure the surface temp directly over the cat next time I have it running.

 

[begreen]

A 3 log fire would be pretty tiny in our stove. It's not much fuel. That sounds more like directions for a startup fire to establish the coal bed. I think you will be burning 6 log fires when winter weather settles in.

 

[bladeofanduril]

A 3 log fire would be pretty tiny in our stove. It's not much fuel. That sounds more like directions for a startup fire to establish the coal bed. I think you will be burning 6 log fires when winter weather settles in.

Ok, that's good to know. The Jotul manual isn't exactly the most clearly written thing. I'll see how much further I can push it with more fuel.

 

[Todd]

Is that where Jotul recommends thermometer placement? I know they recommend off to one side on my F45 but it’s not the hottest place on the stove so I just place it near the center. Seems like you’d want to monitor the hottest spot?

 

[bladeofanduril]

Is that where Jotul recommends thermometer placement? I know they recommend off to one side on my F45 but it’s not the hottest place on the stove so I just place it near the center. Seems like you’d want to monitor the hottest spot?

The manual for the v3 doesn't specify where to take the surface temp, despite needing to know what the surface temp is for the break-in process. The manual is probably my only real complaint about this stove so far.

 

[Todd]

I’d probably just place it somewhat centered then. Try and keep it under 700. It wouldn’t hurt to use a flue thermometer as well. I watch that more than anything.

 

[bladeofanduril]

I’d probably just place it somewhat centered then. Try and keep it under 700. It wouldn’t hurt to use a flue thermometer as well. I watch that more than anything.

Would placing one on the flue connector of the stove work? Its connected directly into stainless liner that is non-magnetic.

 

[Todd]

Would placing one on the flue connector of the stove work? Its connected directly into stainless liner that is non-magnetic.

This stove must be in a fireplace? It won’t give you accurate flue temps unless you taking readings further up. Some people insert a digital probe into their liners to monitor flue temps. Still others just use an IR thermometer so they can take readings wherever.

 

[bladeofanduril]

This stove must be in a fireplace? It won’t give you accurate flue temps unless you taking readings further up. Some people insert a digital probe into their liners to monitor flue temps. Still others just use an IR thermometer so they can take readings wherever.

Yup, set in the fireplace. I have an IR that I can use, but can't see much of the liner.

 

[js21]

I’m getting similar response from my Jotul F500 V3
Combustión temperature at 1200, 400 surface right rear and flue temp of 400.

Is this normal? To keep combustion gas between 500 - 800 it has to be a small burn with intake turned down to 1/4. Thanks

 

[begreen]

I’m getting similar response from my Jotul F500 V3
Combustión temperature at 1200, 400 surface right rear and flue temp of 400.

Is this normal? To keep combustion gas between 500 - 800 it has to be a small burn with intake turned down to 1/4. Thanks

The surface temp is not high. By combustion, do you mean the catalyst temperature? 1200º cat temp is fine at the peak of the burn.
Is the flue temp being measured with a magnetic thermometer on single-wall or probe on double-wall stovepipe?

 

[js21]

The surface temp is not high. By combustion, do you mean the catalyst temperature? 1200º cat temp is fine at the peak of the burn.
Is the flue temp being measured with a magnetic thermometer on single-wall or probe on double-wall stovepipe?

Magnetic on single wall. I also have IR reader get about the same. I have pushed it and can get the flue to 450 but combustion is around 1400 degrees or a little higher while surface is measuring close to flue. The hottest temp that I read on top is right rear every time .

 

[begreen]

That's a fairly high flue temp which indicates a lot of waste heat heading up the flue. The actual flue gas temp is about double the surface reading. A 400º surface reading =~800º flue gas temp. Is there a tall flue system on the stove?

 

[js21]

That's a fairly high flue temp which indicates a lot of waste heat heading up the flue. The actual flue gas temp is about double the surface reading. A 400º surface reading =~800º flue gas temp. Is there a tall flue system on the stove?

20ft chimney from the wood stove. So a good rule of thumb should be surface x 2 = gas combustion temp?

 

[stovexxx]

That's a fairly high flue temp which indicates a lot of waste heat heading up the flue. The actual flue gas temp is about double the surface reading. A 400º surface reading =~800º flue gas temp. Is there a tall flue system on the stove?

reading here and there approximately these are the temperatures v3. the funny thing, the combustor does not transmit to the top, a high temperature, since there is a huge discrepancy between the combustor and the top temperature, and therefore it all ends up in the flue. What do you think about ?

 

[js21]

My concern was the temp so high on the combustion thermometer compared to the flue magnetic and surface temp. I didn’t think the flue magnetic thermometer was high I figured that was probably in-line with the surface temp. In the past on an old Drolet steel insert I would only start to dial it back when temps on flue magnetic thermometer pushed past 500 degrees. I don’t have much doubt that I could push everything higher just afraid I will damage the catalyst .

 

[stovexxx]

My concern was the temp so high on the combustion thermometer compared to the flue magnetic and surface temp. I didn’t think the flue magnetic thermometer was high I figured that was probably in-line with the surface temp. In the past on an old Drolet steel insert I would only start to dial it back when temps on flue magnetic thermometer pushed past 500 degrees. I don’t have much doubt that I could push everything higher just afraid I will damage the catalyst .

your old drolet, when you had 500 flue temp, how much top temp was ?

 

[js21]

If I remember correctly it was always close to each other.

 

[Robert Watson]

I have an IR thermometer, and the hottest place I found on the Jotul F500 V3 is the right side corner (front or back). The left side was cooler, for some reason... The difference between left and right is about 100 F.

 

[bladeofanduril]

I have an IR thermometer, and the hottest place I found on the Jotul F500 V3 is the right side corner (front or back). The left side was cooler, for some reason... The difference between left and right is about 100 F.

View attachment 317817

The same is true on mine. The airflow through the unit seems to favor the right side. That's also the side of my cat that clogged up (on the back side!).

 

[Robert Watson]

I'm curious about your cat clogging. How often do you clean it? Do you take the lid off and remove it for cleaning? How often do you use your stove? Ours is brand new. We brush the face of the Cat with a paint brush when we remove the ash pan. Do you use any cardboard to start your fire? How do you clean your Cat?

 

[bladeofanduril]

I'm curious about your cat clogging. How often do you clean it? Do you take the lid off and remove it for cleaning? How often do you use your stove? Ours is brand new. We brush the face of the Cat with a paint brush when we remove the ash pan. Do you use any cardboard to start your fire? How do you clean your Cat?

Sorry for the late reply. Last season (my first) I just checked the front of the cat for fly ash and brushed it off as needed. I didn't remove the top plate or do anything more in-depth for it. The manual doesn't say it needs anything else. The stove was run almost constantly all winter.

This year, after replacing the cat, I'm using canned air to blow through the cat (only when the stove is cold) and keeping a close eye on it for any signs of warping or deterioration. I'd prefer not to remove the top plate frequently, for fear of losing a good seal, but I may pull it to check on things. These cats are $700+ and I've heard rumor that the "25 year warranty" only covers one replacement. It seems impossible to me that one of these cats will last 25 years.

 

[begreen]

The top plate is gasketed. The gasket shouldn't need replacement more than a door gasket.
A replacement cat from Midwest Hearth is $370.

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