Who has a Kozy Heat Z42? Pros? Cons?

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Josh Ottenbacher

New Member
Feb 25, 2015
Northern Michigan
I am getting really close to purchasing this unit. Im currently running a freestanding woodstove on my main floor which is a really open floor plan. My concerns/questions are burn times? Anybody running ducts off of it? Ease of being able to control the burns ( shutting it down if too warm ) and overall satisfaction of people who have been using this unit. This will be my primary source of heat. My main floor is 1100 sq ft And has a 17ft cathedral ceiling with a 500 sqft loft area above it. I also have a big family room directly underneath where I'm planning on installing it which is why the duct option is appealing. I live in Northern Michigan so I will see cold temperatures in the winter months.

Thanks for any feedback it will be greatly appreciated!!!
I've installed several of them many we run one as a display. It's a respectable heater.
Why are you going this route rather a new freestanding stove?
I've installed several of them many we run one as a display. It's a respectable heater.
Why are you going this route rather a new freestanding stove?
I've installed several of them many we run one as a display. It's a respectable heater.
Why are you going this route rather a new freestanding stove?

We like the idea of the fireplace look and it wouldn't stick out into the room as much. I can't say I've totally ruled out a newer free standing stove that would be way more efficent than my early 1990 defiant/encore But this idea seemed like the best of both worlds for looks and efficiency. Burntime is a concern but it seems to have a large firebox which is appealing as well.
I really don't think it will compete with a freestanding stove. The blower is loud and it relies heavily upon it. Not unlike other ZC fireplaces though.
We are in our 2nd year with ours and are overall happy with it. Burn times are my biggest complaint. I find myself loading every 3-4 hours with the stove around 250-300* (measuring just above the doors). I'm still learning my stove and have never packed it full like a lot of others- at most 3-4 splits, which I'm sure if effecting my burn times. The kozy puts off some good heat and the fan isn't very loud. I would have done a free stander if our house was more conducive for one but am overall pleased with the kozy.
Glad to hear you like yours. I would definitely be loading full trying to achieve an overnight burn. Are using the ducting option? Is this your primary source of heat? Is the dampering system touchy?
We did not opt to use the extra ducts. The stove is not our primary heat source- we have heat pumps (we live in Georgia) and when the temp gets around 30 they really struggle without turning on the heat strips- kozy earns its stay during these temps. I haven't found the air intake to be touchy at all
A freestanding stove will not have ductable heat. The Kozy does.
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I had a Z42 installed in sept. 2010 (maybe 11....can't remember). Didn't go for the duct option at the time, kinda wish i had though. aside from having to replace one of the fans on the blower last winter its been great (prob just all wrapped up with dog hair so i can't really blame KH). blower isn't so loud that it bothers us watchin TV unless you crank it to full power which i've never had to do. it heats the first floor and the second floor hallway of a 2500sqft center hall colonial in NW NJ built in 1995 with little effort. firebox is huge. I can stuff it with anything north of soft maple at ~10pm and have plenty of restart coals at 5:30-6 or whenever i get to it. with overnight lows in the single digit below and above zero this winter the house has been 68-ish waking up after an all night burn. last night i got lazy cuz it was so warm out (19!) and left a lot of empty space in there and i still had a warm downstairs and some coals to restart. air control is simple but very effective once the box is full and burning i can shut it as far as it will go and still have clean glass in the morning. Ive never worried about it getting too hot...did some infra red pyrometer checks the first winter don't remember what temps i was seeing but wasn't concerned.
I'm feeling better about this decision now that I know the unit will accomadate my sq footage and floor plan and still be efficient enough to not have a cold house in the morning and be restarting fires. I really appreciate the feedback / Thank you
Correct me if I am wrong but I do not think the Z42 has any adjustable burn rate controls
or dampers for intake or chimney etc. You can fill it full of wood but it is going to burn
up pretty fast if you cannot slow it down. I have been running a 231ZC for 12 years
with approx same size firebox I think. If I am right about the lack of adjustable controls,
I notice that the Z42 utilizes an outside air source and Kozy company sells a butter fly valve
setup that works with the intake air source for my 231ZC that would no doubt work
on your stove also even though it would be against EPA regs to use on your stove
I would think. If you go that route try to order the air valve kit separate from your
stove and conceal your true intent from the mfg and dealer etc.

Because of your 17ft ceilings and loft etc I also do not think the Z42 will be big enough
to heat your space in your climate area during the coldest nights. Do you have lots of
ceiling fans to blow the heat down from the ceiling ? Otherwise I think you could
have 80 degree temps at the ceiling and 50 degree temps at the floor.

Last year I recommended that a friend buy the 241ZC instead of the Z42 because of the
controlability of burn rate. Although the 241ZC is not EPA certified, I believe that if
you choose to burn it wide open like the approved EPA Z42 stove which does not give
you a choice, I think the 241ZC it will burn just as clean..... but it is your choice to make.... whether to burn clean or not. I love the Kozy Heat product and company but I think all of their wood burning products will have to be phased out by the end of the year
due to EPA regs.
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The Kozy Z42 has an EPA listing of 3.3gm/hr. Why do you think it will be phased out at the end of the year? It is well under the 4.5 gm WA state emissions requirement. That means it should pass EPA step 1 requirements as well.

EPA’s final rule updates existing emission limits for adjustable burn-rate stoves in two steps over a five-year period:
  • Step 1: The rule becomes effective 60 days after it is published in the Federal Register. At that time, PM emissions limits will be identical to those currently required by the State of Washington for noncatalytic stoves. Most adjustable-rate woodstoves manufactured and sold in the U.S. today already meet the Washington state emission standards; these stoves will be deemed automatically certified under the final rule.
    • To ease the transition to cleaner stoves, EPA’s final rule will allow woodstove retailers to sell existing inventory until December 31, 2015. After that date, any new woodstoves sold at retail in the U.S. must meet the Step 1 emissions limit.
  • Step 2: Five years after the effective date of the rule, woodstoves will have to meet stronger emissions limits (see table below).
I'm confused by the statement that the Kozy Z42 has no adjustable air control. What is this?
Who has a Kozy Heat Z42?  Pros? Cons?
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I've been heating my 3 bedroom, single story, 1800sq ft home with a z42 since February 2010. We are happy with it, and chose it mainly because we didn't want to lose seating area in our living room. I'd love to have a freestanding stove, but this was a nice compromise. We have a propane heat pump/furnace, set at 65, and it never turns on.

I set aside 4 cords a year and really only burn 3 and change. Burn times: that's my biggest complaint, if I HAD to come up with something, but at the "end" of a 5-6 hour burn, my thermostat regularly reads in the upper 70's or even 80 with outside temps in 20's or even teens. Bedrooms at each end of the house will read in the upper 60's.

The stove burns longer and hotter when loaded north/south (front to back), so cut your wood accordingly. I rarely run the fan at max, maybe at night, as it is a little loud. When we're home, I run the fan on the lower settings with the bottom grate open, and airflow to the room is just fine.

IMHO, it was a solid compromise to giving up a floor space when there's already a fireplace.
I knew someone would call me out on that.... If I recall correctly, it's 18", 19 max, but I've slept since I ran the saw last.
Of course it has an adjustable air intake lever! It's on the right side below the door.
Yes, I don't know where that statement was coming from.
Correct me if I am wrong but I do not think the Z42 has any adjustable burn rate controls
or dampers for intake or chimney etc. You can fill it full of wood but it is going to burn
up pretty fast if you cannot slow it down.
Thank you for correcting me about the adjustability of the air intake on the Z42.
I could not see any levers in the brochure and there was no mention in the brochure
so I thought that was how they got the stove to meet EPA regs. I am a 14
year happy user of the Kozy 231ZC that is 11 inches taller with the same size
firebox. That extra 11 inches up top is where they house the secondary burn chamber
and I would really like to know how Kozy co. managed to keep and improve on
secondary burning with the shorter Z42 as it seems to me they drastically reduced
the secondary chamber size. Kudos to Kozy as I did not know they met
the new EPA regs with an impressive pollution rating.

One hint about the what some think is a noisy fan as supplied with the unit.

If you use the remote heat duct options, you can mount fans remotely inside the
duct to promote air flow to wherever you want it even if it is into the same room
as the fireplace and the fan noise will be completely inaudible just like a modern
HVAC unit.

I was also able to draw warm air from the "closet" that I installed the firebox (231zc)
in. I created about 3 inches of space all around the stove that was lined with concrete board
behind which I had 2 inch sheets of foam board. Basically I installed the wood stove
inside a sealed insulated plenum through which I can have some airflow when I
turn on a fan. I initially found a company that sold lots of fans when I needed
a fan for the exhaust ducting over the stove in my kitchen that had two additional
floors above to move the air through before it reached the roof. With the remote
fan in that situation it was totally quiet over the stove and then I got carried
away with other options such as quiet bathroom and shower venting and ultimately
customized ducting for my Kozy Stove.. Beware there is a drawback to quiet and
that is you cannot tell the fans are running. I ultimately had to get wall switches
that light up when the switch is turned on.

My Kozy stove is installed on an outside wall but I am reasonably sure that
I am not letting much wasted heat radiate through the wall when I have my
fan on that ventilates the stove "closet".

The biggest downside is when you lose electricity as you can not extract
nearly as much heat with out the fans. Fortunately that is very rare.

I cant really decide if I were to build another house today whether I would
want another 231ZC or the Z42 assuming there were no regulatory laws
pushing me on one direction. With the 231ZC it does use the larger
8 inch chimney compared to the smaller 6 inch on the Z42. I think that could
only affect the maximum output which is kind of irrelevant because I think
that any fire that could really use the extra capacity would be a dangerous
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