PSG Caddy please help!

NH_burner

New Member
Dec 4, 2019
58
NH
I bought a used Caddy a few months ago to install in my house (2500sf new construction). Now we've moved in and I've fired it up twice with little success. The chimney is 6" stainless double wall insulated, about 25' of it outside entirely vertical with the exception of a short 30 degree jog around the soffit. Then there is about 3' more of the chimney inside the house and about 6' of double wall stove pipe.

For the first fire I couldn't find my torch so I got it going with a lot of paper first. I smoked myself out for a good 15 minutes or more before the chimney started to pull. I loaded it up and got some good heat out of it but I noticed that when the blower was on, I could feel hot air blowing out of the primary air intake. It was running well so I kind of disregarded it.

Fast forward to tonight, I found my torch so I took a different approach. Still used some paper but I put more kindling in to start with. I also used my shop vac to blow air up the chimney to force draft until it heated up. This seemed to work pretty well but I had to keep it going for at least 30 minutes, maybe more, well past the point of a large hot fire. Again, when the blower came on air was coming out of the primary air, the secondary air port on the left side, and the small hole beneath the door. The only spot that was still drawing air in was the right side secondary air port. Also when the blower would come on it clearly had an affect on the fire. At times at first it seemed to increase the flame but then it was putting the fire out and sending clouds of smoke out of the primary intake until I opened the door and the fire caught again. This happened several times. After about an hour I had to take the burning logs out and put the fire out even though it appeared to be burning good and hot because I couldn't get it to stop smoking.

Checked the moisture content after and it's 23%.

I'm thinking there's no way the blower should be affecting what's happening in the fire box. I plan on removing the bricks and inspecting everything as best I can but I'm hoping some people on here may be able to help point me in the right direction ahead of time. Thanks!
 

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NH_burner

New Member
Dec 4, 2019
58
NH
I will add that for the first fire I was using the red oak scraps from flooring and trim so it was likely very dry. The wood tonight was regular hardwood firewood, not sure the species.
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,362
Wisconsin Dells, WI
Sounds like you may have a rotted firebox....? Once you remove the firebricks and inspect you should be able to see if this is the case. If this is true, sucks someone would have sold it knowing this. :mad:

Warm air circulation blower should have zero effect on the fire...and it should NOT be blowing air out places which are designed to supply air to the fire for combustion.
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,816
NE Ohio
At 23% MC you will struggle to make that burn well...and it sounds like your draft may not be great...have you measured it? Does the chimney meet the 10-3-2 rule? Big trees nearby?
As far as the blower affecting the fire/blowing out the intake holes...I'd strip the outer jacket off of 'er and inspect every square inch of the firebox/heat exchangers...I found a cracked weld on one of my Tundra heat exchangers (basically same as Caddy) it looked like it was not welded the best to begin with. It was not affecting things near to the degree that you are seeing though...my guess is that you would have to have a pretty big crack/hole to act the way yours is.
Maybe look at the bottom of the center HX tube first (toward the back)...I have heard of those rotting out.
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,816
NE Ohio
Here is the post/pics I made on my HX crack...
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,362
Wisconsin Dells, WI
At 23% MC you will struggle to make that burn well...
While it's not ideal, the 24% stuff I've been unfortunately burning off and on a lot of this winter burns and heats just fine in the temps we have been having. I also have no issues getting it to take off after lighting a fire with simple newspaper/kindling. I just throw the splits on after the damper opens to '3' and walk away like I have always done. I've just noticed shorter burn times, but that's about it. Definitely not getting the overall BTU's of the drier stuff due to the shorter burn times, but it's been doing the job. I think his big issue is why the blower is blowing the fire out. That would be the very concerning part to me. !!! I'm also guessing his draft may not be enough based on issues getting it to draft on a cold firebox.
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,816
NE Ohio
I just throw the splits on after the damper opens to '3' and walk away like I have always done
Exactly...easy peasey with a Kuuma...not so much with a unit where the fire is not actively managed...but yeah, I agree, first order of business is figuring this blower issue out.
 

NH_burner

New Member
Dec 4, 2019
58
NH
and it sounds like your draft may not be great...have you measured it? Does the chimney meet the 10-3-2 rule? Big trees nearby?
dwyer mano is in the mail along with a thermostat. Chimney does meet the 10-3-2 rule. The lot is surrounded by big trees but not really close proximity to the chimney. Probably 200' at the closest. I'll get a pic of the chimney when I get home later. It is however a very windy lot and last night we had potential for 50mph gusts.

Maybe look at the bottom of the center HX tube first (toward the back)...I have heard of those rotting out.
I'll start there and with the inside of the firebox. I'm sure I'll have to end up pulling the skin off of it but that means disconnecting ductwork too which is kind of a pain.

sucks someone would have sold it knowing this.
Yeah, there are sucky people out there. Overall I've had pretty good luck with Craigslist, but this would be my 2nd time getting boned on a wood furnace, lol.
 

NH_burner

New Member
Dec 4, 2019
58
NH
Another thought I had was that there may be too much pressure in the ductwork. I'll check the static pressure when the mano comes in to see if it is in spec. But even if there was too much pressure in the ducts the firebox or heat exchanger would have to be compromised before the blower air could find its way in, right? There aren't any gaskets that could be leaking?

With a rotted firebox or HX, shouldn't the blower be sending smoke and combustion byproducts into the living space? Now it did get a little smokey in the living space last night but I attributed that to the fact the basement was full of smoke. And it was not enough smoke upstairs to activate the smokes/CO's, and since it's new construction there are plenty of them!
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,362
Wisconsin Dells, WI
Another thought I had was that there may be too much pressure in the ductwork. I'll check the static pressure when the mano comes in to see if it is in spec. But even if there was too much pressure in the ducts the firebox or heat exchanger would have to be compromised before the blower air could find its way in, right? There aren't any gaskets that could be leaking?
correct. The internal firebox and air jacket should be completely separate and no amount of duct pressure should compromise it.

With a rotted firebox or HX, shouldn't the blower be sending smoke and combustion byproducts into the living space? Now it did get a little smokey in the living space last night but I attributed that to the fact the basement was full of smoke. And it was not enough smoke upstairs to activate the smokes/CO's, and since it's new construction there are plenty of them!
Not always. The blower would be adding air to the firebox and the draft should be creating a negative pressure inside the firebox adding to the air coming in from the crack/hole. The negative pressure in the firebox would keep anything from leaving it. If there was ever a positive pressure occurrence, then yes, I would expect to see some smoke spillage out the hole/crack. This is how I see it anyway, could be wrong though. I'd get a hold of a CO monitor, preferably one which displays the max PPM of CO, and place it somewhere in the house. I have one right near one of the heat registers and check/clear the max PPM every few days. I do see some very low readings (teens) once in a awhile in the dead of winter when loading on a good bed of coals when I get some smoke spillage (I removed my smoke baffle as it drove me nuts). Seeing those low levels, knowing the source of them and knowing the monitor is that sensitive gives me peace of mind it's doing it's job.

<EDIT> Although you are seeing smoke being pushed out the air intake, there could very well be occurrences where the firebox is under positive pressure.
 
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laynes69

Minister of Fire
Oct 2, 2006
2,483
Ashland OH
The exact point that where you would have rot in the exchanger would be where the heated side meets the cold air return. I had 2 fire boxes and both developed holes at that point. I fixed it by cutting off the old tube on the return side and implanting a section of rigid stainless (which I also wrapped in ceramic fiber insulation). Not saying that is it....but the older design like that condenses the gasses at that point. I'm positive that's why they did away with that design.
 

NH_burner

New Member
Dec 4, 2019
58
NH
The exact point that where you would have rot in the exchanger would be where the heated side meets the cold air return. I had 2 fire boxes and both developed holes at that point. I fixed it by cutting off the old tube on the return side and implanting a section of rigid stainless (which I also wrapped in ceramic fiber insulation). Not saying that is it....but the older design like that condenses the gasses at that point. I'm positive that's why they did away with that design.
To be clear, you are talking about right here?
 

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laynes69

Minister of Fire
Oct 2, 2006
2,483
Ashland OH
Go back further into the cold air return. They warranties my firebox but I was the original owner. You could try....but at this point I dont know. It's not too hard to tear off the jacket...however you need a corrosion resistant metal and have it insulated. I actually made my connection into the hot side.
 

NH_burner

New Member
Dec 4, 2019
58
NH
Time for an update. So I definitely solved my startup drafting issue. Take a look at the pics of the chimney, see if you can find what's wrong!

So then I stripped the jacket off to inspect the firebox. I checked every square inch and for the life of me I can not figure where the blower air is making its way into the firebox. Everything looks great, all the welds, if, etc. Only minor, minor surface rust on the firebox sides. The only thing I noticed is that the bottom half of the center hx tube was not ever welded.
The side tubes were welded all around. Even still, with all the lights off in the basement I used a flashlight and no light was getting through. I think it may be sealed from the inside.
So that got me to thinking, maybe the blower was not pushing air out of the firebox but was actually pulling air out of the firebox by creating a negative pressure in the basement. Especially where there was little to no chimney draft.

Seem plausible?
 

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brenndatomu

Minister of Fire
Aug 21, 2013
4,816
NE Ohio
So I definitely solved my startup drafting issue. Take a look at the pics of the chimney, see if you can find what's wrong!
Hmm...not seeing it...I'll take a flyer though, cleanout cover not put on?
IIRC on my Tundra the HX tubes were welded on the inside some places, on the outside others.
Is your blower hooked up to cold air return ducts? Negative pressure from the blower can cause negative draft...but if cold air return is hooked up then that shouldn't cause any trouble.
 

NH_burner

New Member
Dec 4, 2019
58
NH
cleanout cover not put on
You guess It! I put the chimney up in the summer, forgot about the clean out cover... boy do I feel like a dope.

Blower does have cold air return hooked up, but it was not taped at the connection to the furnace. Doesn't seem like that's enough of an issue but I don't have any other explanation.
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,816
NE Ohio
Look at the positive...you have done a "fine toothed comb" inspection, and now know what you have...and have gained familiarity with it too!
 
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laynes69

Minister of Fire
Oct 2, 2006
2,483
Ashland OH
The tubes are either welded inside or outside but rarely both sides. I think they are all like that. Glad to see you got things inspected and hopefully taken care of! There will always be air leaking from the lacket around the firebox and that is a good thing. It helps to keep things cool. However, if you do have smoke spillage, its easy to get pulled into the return and into the house. Turning off the furnace when loading is one way to prevent spillage.
 

NH_burner

New Member
Dec 4, 2019
58
NH
:rolleyes:Ok folks, I have an update. Started a fire today and the difference was night and day! Even with a cold chimney there was very little smoke back when getting the fire started, so that problem is no more. But, the blower is definitely still affecting the air inside the firebox. When it comes on hot air pours out of every intake.

I'm gonna let the fire go out tomorrow then manually turn on the fan and see if I can feel where the air is coming in from. Its running good and heating the house but with air coming out of the intakes I'm not getting a secondary burn and not running efficiently.

Chimney temps have been rather cool too. I don't think I've hit 300 but the pressure is right on point.

I might also be burning some really wet stuff... like 29%... But it's burning easily
 

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brenndatomu

Minister of Fire
Aug 21, 2013
4,816
NE Ohio
I might also be burning some really wet stuff... like 29%...
Gonna be tough to get secondary burn running wood that wet.
So if you pile up 100 lbs of wood, 29% of that is water...or, by weight, almost 4 gallons! (8.34 per)
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,362
Wisconsin Dells, WI
But, the blower is definitely still affecting the air inside the firebox. When it comes on hot air pours out of every intake.
Do you have a window downstairs you can open to provide some outside air? Just to see if that changes anything.
 
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