Psg caddy

[Eric barber]

installed a psg caddy and fired it up a few weeks ago. It puts off great heat and heats the house up no problem at all. Although when the house isn't calling for heat it builds up a bit of creosote. I have a field controls damper and my draft is set at .05-.06 w.c (I have a 27' chimney with a 6" SS liner that pulls about 1.5-2 w.c wjthout damper). I have one 90* adjustable elbow on the stove and the the creosote was enough to drip out of th seams on the elbow. If I had to guess my stove pipe isn't getting much over 200*. My wood is 2 year aged and has been inside my wood shead so I don't think Wer wood is the problem. it looks like I'm getting really good burns as the bars on the inside of the stove look like a gas grill. I have been thinking about increasing the draft a little to maybe .07-.08 w.c (I know it might burn a little more wood) but I prefer not to have this much creosote. Any input is greatly welcome.
Eric barber
I attached an image of the secondary burn which is how I believe it is supposed to look. I have a video but can't upload it

 

[sloeffle]

We have had our Caddy for about 3 - 4 year and I have never had issues with liquid creosote. Burned some marginal wood one winter and didn't have any issues. I find that if I let mine idle ( damper closed ) it will build up a lot of creosote. Now I keep a small nail between the damper door and the stove so at least I am getting a little bit of air in the firebox. That has helped a lot with creosote build up.

Have you checked your wood with a moisture meter ?

 

[Eric barber]

I have not checked the moisture I will order one today and check it asap

 

[Eric barber]

Also my draft is so much that my damper is always opened at least 1/4 way and on my barometric damper I have the setting all
The way out on .02 and still have to add a little weight to the aluminum adjustment piece to get it to read .05 on my manometer

 

[sloeffle]

Thinking outside the box a little. What about buying some of those compressed wood dust blocks and see if you still have issues with creosote. Do you see smoke coming out of the chimney when your secondary burn tubes are lit ? You should see very little smoke when the secondary burn tubes are lit ( like your pic ).

 

[Eric barber]

I didn't think to look. I will also check that

 

[3fordasho]

I had the same issue when I first fired up my Tundra (same firebox design). Wood was plenty dry, most of it split and stacked for several years and then stored inside.

Besides wood with too high a moisture content (and this is the first thing to eliminate) I think there are several reasons you can have the issue:
1. not initially getting the firebox hot enough to maintain secondary burn to the coaling stage and then #3.
2. new firebrick needs several burns to get moisture out.
3. Never opening the air inlet after the initial charring stage
4. more likely to happen on a cold start (no bed of coals)
5. chimney type - un-insulated, too large, exterior, low draft

In my case I solved the problem be adding a thermocouple and temp control to measure the flue temp in the connector pipe about a foot above the furnace exit.
I have it set to open the air inlet when temps drop to low, ( in my case about 260F). No more liquid creosote dripping out the connection at the furnace.
Not a necessary addition but I did it to somewhat automate furnace operation, I can load a cold furnace, light, set a timer and forget about it till the next reload. The temp control protects from too low and too high flue temps.

200F outlet temp is too low, you will have condensing in your flue at these temps.

The Caddy/Tundra runs pretty low outlet temps by design - I typically see 280-350F during the active part of the burn - compare this to my Englander 30nc which will run 600-700F flue temps during the same part of the burn.

Another indicator is flame in the box - if you have lots of wood in the box and it's well before the coaling stage, you need to see flames in the box, preferably good secondary type. If you have a bunch of wood in the box, no flame but it's sitting there glowing and smoking, you will have lots of smoke out the chimney and low flue temps = creosote factory.

I don't run a barometric damper- They solve high draft problems but they also cool the flue so it's even more important to maintain high enough flue temps.

 

[Highbeam]

I don't run a barometric damper- They solve high draft problems but they also cool the flue so it's even more important to maintain high enough flue temps.

If not overly wet wood, the baro is the problem. That baro damper is wide open sucking cold air into the flue to try and quench the draft. That cold air cools the flue gasses to below the condensation point of the water in the smoke. Yes, even 20% moisture fuel has 20% moisture. A small 50# load of firewood has a full 10# of water to be sent up the chimney. That's way over a gallon.

To solve, add a key damper. The key damper can be set and forget and then the baro will only have to quench a little bit of draft so will only introduce a little bit of cold air.

 

[Eric barber]

My baro is set to open at "2" and this is what I'm reading on my manometer the only way I can get It lower is to add weight to the weight that is on the barometer

 

[Eric barber]

I just realized that my manometer is kind of high on the starting scale but still seems very high when psg recommends a max of .06. But when l correct it using little weights my flu gets cool enough that I can just about rest my hand on it

 

[maple1]

You have a different scale on that manometer. The draft spec is in inches of water column, and that's what the scale on my manometer is in. I don't know how 'feet per minute x 1000' correlates to that?

 

[maple1]

Googled up a chart.

0.06" WC = 981 FPM.

0.1" WC = 1266 FPM.

Think you might have to increase your draft, maybe.

 

[Eric barber]

Does anyone happen to know the conversion?

.06 w.c is .981 fpm ?
Seems correct I also just found the conversion and .06 w.c is 981 which divide by 1000 is .981. So it appears I was having my damper set way too low creating too cold of an exhaust pipe

 

[maple1]

It's not just a cold pipe. It would also impact combustion, so likely more dirties making it to the pipe.

Make sure you zero the manometer too, exactly. And level it, exactly. They are less precise with measurements this low, so a tiny bit out before you measure can throw readings off.

 

[Eric barber]

It's level and zeroed out. I'm going to order a w.c gauge though. Thanks guys. I'm sure sooner or later I'll be back asking for more help.

 

[brenndatomu]

In my case I solved the problem be adding a thermocouple and temp control to measure the flue temp in the connector pipe about a foot above the furnace exit.
I have it set to open the air inlet when temps drop to low, ( in my case about 260F). No more liquid creosote dripping out the connection at the furnace.
Not a necessary addition but I did it to somewhat automate furnace operation, I can load a cold furnace, light, set a timer and forget about it till the next reload. The temp control protects from too low and too high flue temps.

I copied this setup for my Tundra...SLICK!
I think many (most) wood furnaces would benefit from adding a temp controller

Seems correct I also just found the conversion and .06 w.c is 981 which divide by 1000 is .981. So it appears I was having my damper set way too low creating too cold of an exhaust pipe

If that is the case then you are in the range of normal, they call for -.04 to -.06" WC, so that would be .801 to .981 FPM on your meter, your pic shows your draft is right in the middle of that range (-.05" WC) no?

 

[Eric barber]

If that is the case then you are in the range of normal, they call for -.04 to -.06" WC, so that would be .801 to .981 FPM on your meter, your pic shows your draft is right in the middle of that range (-.05" WC) no?

Yes. My gauge is reading .900. So seems I have a good draft! Thank you gents

 

[brenndatomu]

Oh, and that adjustable elbow you mentioned, those are generally frowned upon, for that very reason, leaking creosote.
That and most of them will come apart pretty easily, especially when they are red hot, like during a chimney fire, right when you DON'T want it to fail!

 

[Eric barber]

Ok. I'll definitely be changing that out then Thank you

 

[brenndatomu]

Ok, so assuming that your draft setting is OK, then we haven't solved anything. I still wonder about the wood, does the secondary burn continue on long term (like a couple hours) even if the tstat never calls for heat? If not then that almost certainly points to wet wood as long as your draft isn't dying off, and it sounds like you have a good chimney setup, so I doubt that is an issue.
Just curious, how big of an area are you heating and what is your usual heat bill like? (like how much gas/oil/electric do you normally go through per winter?)
Once the weather cools off more things will likely work better too. Spring and fall can be tough with a wood furnace (creosote city). I have a small wood stove in my fireplace that I use to heat the place during those light heat load days.

 

[Eric barber]

The draft settings were not ok, but they are fixed now
I heat 1700 sq feet. Dunno how much oil I would use because last year i was running a 25 year old jensen wood furnace. We had a really nasty winter and I used about 3.5-4 cords maybe burned 3/4-1 tank of oil all winter (hot water) and during the day when the Jensen ran out of wood). I order a moisture gauge and it will be here within a week or so. I will defiantly post results. As far as secondaries I haven't watched it for long but I will make a point of It and let you know.

 

[maple1]

I copied this setup for my Tundra...SLICK!
I think many (most) wood furnaces would benefit from adding a temp controller

If that is the case then you are in the range of normal, they call for -.04 to -.06" WC, so that would be .801 to .981 FPM on your meter, your pic shows your draft is right in the middle of that range (-.05" WC) no?

True on the pic, but first post indicated it was set at 0.05-0.06, so if that was a .5-.6 reading on the manometer scale at FPS, that would correspond to a draft of only around 0.02" WC.

Keep us posted on how things go, Eric.

 

[Eric barber]

True on the pic, but first post indicated it was set at 0.05-0.06, so if that was a .5-.6 reading on the manometer scale at FPS, that would correspond to a draft of only around 0.02" WC.

Keep us posted on how things go, Eric.

Yes it was my mistake i didn't realize there was different Manometer gauges. I just assumed it was all the same and I had a higher scale one. Also it didn't click that I needed .05wc and I was at .5fpm

 

[sloeffle]

The draft settings were not ok, but they are fixed now
I heat 1700 sq feet. Dunno how much oil I would use because last year i was running a 25 year old jensen wood furnace. We had a really nasty winter and I used about 3.5-4 cords maybe burned 3/4-1 tank of oil all winter (hot water) and during the day when the Jensen ran out of wood). I order a moisture gauge and it will be here within a week or so. I will defiantly post results. As far as secondaries I haven't watched it for long but I will make a point of It and let you know.

My bet is that you will use about a third less wood and your oil usage will drop some. It is a pretty impressive unit once you get it dialed in.

 

[lexybird]

Any time I have seen liquid creosote it has always been due to the same thing . ..Too much moisture in the wood ! It's gotta come from somewhere .