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Pyroclassic IV wood fire

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Pyroclassic IV wood fire

Posted 15 Nov '09 06:33 AM

Hi, has anyone had or known someone who has had a Pyroclassic IV wood fire? It is reportedly one of the most efficient fireplaces on the market. I am interested though to hear from anyone as to its performance. The manufacturer states it heats a home 200-250sqm. It also has a 3.7kw wetback and claims to burn overnight. Another option I am looking at is the Osburn. Can anyone comment?

Re: Pyroclassic IV wood fire

Posted 15 Nov '09 09:11 AM

To "burn overnight" means reducing the airflow so the fire ticks away very very slowly - this reduces efficiency, results in less clean a burn and more nasties produced. Some types of wood, when burnt under such conditions, creates volatiles which due to incomplete combustion ends up depositing on your chimney and becomes incredible corrosive.

Although used as a selling point, "burning all night" is not actually a good thing....

We use a "gourmet cooker" with wetback - only because we want the oven and cook tops - not recommended due to high cost and rude salespeople - but the wetback is about 6kW and heats 450 litres of water over an evening by about 20 deg C. We run at at full bore and never at "low revs" because the wetback already has a cooling effect in the fire which reduces burning efficiency.


Re: Pyroclassic IV wood fire

Posted 15 Nov '09 06:30 PM

I have to whole heartedly disagree with you there mate. I work shift work, my wife is pregnant and come february we will have a new born baby. The ability to burn overnight is a very good thing. It means we dont have to be constantly lighting the fire. The Pyroclassic is one of the most clean burning, green energy efficient fires on the market according to the manufacturers and according to NZ Consumer magazine. I am after feedback on the model of fire rather than negative comments which really of no help at all. Cheers

Re: Pyroclassic IV wood fire

Posted 07 Mar '10 10:15 AM

What you say about the nasties produced when a woodburner is shut back overnight does not apply to a Pyroclassic. You are unable to control the air supply, other than at startup. The air supply is controlled automatically and the fire always burns at peak efficiency.

These fires are outstanding and I would never have anything else. The time it will burn is controlled by the amount of wood that you load. It is quite neat to stand up on the back lawn and see that your chimney is the only one in the street with no visible smoke coming out of it. Never get any creosote buildup because of the high temperature combustion.

Re: Pyroclassic IV wood fire

Posted 07 Mar '10 06:55 PM

Hi Wainuiomata

Couple of questions for you:

Do you have a wetback?

How long does this fire burn if you fully load it with firewood, given that this is the only way you can make it "burn overnight"? I am assuming dry firewood.


Re: Pyroclassic IV wood fire

Posted 08 Mar '10 10:49 AM

Don't have a wetback fitted yet. Plan to fit one though.

It all depends on the wood you use. Last year we had old really dry borer ridden rimu and it would burn overnight. There is a fixture in it to prevent you overloading it with wood. This means it always burns at peak efficiency and can't be overloaded. I suppose I was putting in two pieces of rimu 4x2 about 400 - 450mm long at bedtime and was able to get it going from the embers in the morning. Very easy to get going from almost nothing due to the design of the starting air vent. It is like having a vacuum cleaner on blow aimed right where you need it. Also have very thick heavy ceramic firebox that holds the heat for a long time. Notice that the house is still warm in the morning, even if the fire is almost out.

Will be using gum in it this winter so should be even better and longer burning.

Re: Pyroclassic IV wood fire

Posted 08 Mar '10 08:11 PM

Sounds great.

Thanks for reply.

It would be interesting to hear how the gum firewood goes after you've had it on for a couple of times: burns longer and/or hotter in that firebox???


Re: Pyroclassic IV wood fire

Posted 20 Apr '11 08:59 AM

Had heard these logburners were legendary so visited the showroom yesterday at 8 St Andrews Rd just out of Havelock North. Currently have a Jotul F3TD cast iron burner, nice to look at but no overnight burn capability as I refuse to burn them on low. We have decided to replace it with a Pyroclassic, as they are enormously impressive and simple to operate. Smaller than they appear in pictures. Long and narrow like the original freestanding Kents and lady Kitcheners. And very frugal on wood. Our house is not particularly well insulated, so I want a burner that will keep the house warm by burning continuously (i.e. all winter). The Pyroclassic will do this. It is a heat storage unit rather than a wood burner due to the ceramic cylinder which as I recall is 38mm thick. Also there is less ash ending up in the room, as the fire burns the wood almost completely to nothing and you don't need to clean them out very often. One of the critical things mentioned on the Pyroclassic website, which I totally endorse, is to make sure the wood is as dry as possible before burning it. Pyroclassic have just renewed their website, worth a look. Will write again once we have the new burner installed, and up and running. There is a lot of good science in the design of this burner (the old DSIR developed it).

Re: Pyroclassic IV wood fire

Posted 15 Aug '11 11:10 AM

Further to the above post, we have now had a Pyroclassic installed for a month or two. Some comments:

1) Maximum heat capacity is less than that of the previous Jotul.

2) Overnight burn capability is good but you need to load it up just before going to bed.

3) Once hot, you can't open the door easily and have to let it burn down for a while before loading wood in again.

4) There is a lot less ash to clean out.

5) It likes smaller logs, up to 3 inches in diameter which is not huge.

6) It keeps our house warmer overall.

7) Price was $5100 all up including shifting the old burner out (we still have the Jotul and may put it in our shed).

8) Wetback works well without spewing lots of boiling water onto the roof.

Re: Pyroclassic IV wood fire

Posted 15 Aug '11 08:18 PM

am pleased that yours works well with wetback! assume it was factory wetback. i have only experienced 2 pyro's 1 was freestanding in an old large house & the owners were ecxtatic the other was in a small house with a wetback intertied with solar & although the owners were happy with heat output i was undewhelmed,& the water heating was far from satisfactory i really dont know why people dont use the flue heat for wetback either as sole water heater or as a secondary boost

Re: Pyroclassic IV wood fire

Posted 10 Nov '13 11:49 PM

Now that you have had this fire in for several years, what's the verdict? Is it worth the money? Does it do the job. Cheers Doug

Re: Pyroclassic IV wood fire

Posted 07 Apr '14 03:00 AM

Hi I am also looking at the Pyroclassic as an option for a 2 year old house. One of the things that attract me is the fact it uses less wood and it isn't a huge bulky thing to look at. I would really love to hear from people who have one who could share their truthful opinions on them. Thanks very much.

Re: Pyroclassic IV wood fire

Posted 07 Apr '14 03:59 AM

Yes I think it's worth it. However if I could do it again I would have set the fireplace a bit higher with the optional log storage underneath.

I have noticed the steel lip at the bottom of the door has warped over the 3-4 years I have been using this fireplace, and it has blocked off one of the air inlets. I will take that up with the installer.

Also, the installer (Watermart in Masterton) forgot to put a regulator on the hot water cylinder when the wetback was attached, resulting in near boiling water coming from the taps, and putting cracks in the (new) bathroom sink and wrecking the kitchen tap.

Re: Pyroclassic IV wood fire

Posted 07 Apr '14 06:19 AM

Hi Richard thank you for your reply. Unfortunately because the cylinder isn't set up for a wet back and it's only 2 years old it isn't really worth putting in the wetback. Are you pleased with the heat it puts out and do you think it uses less wood than a conventional wood burner? My husband is rather skeptical of the size of the fire box. What sort of wood do you use on it? We would mainly be using pine. Thanks again

Re: Pyroclassic IV wood fire

Posted 07 Apr '14 07:05 AM

Hi Penny, I think from memory (I'm away from home currently) the box will take pieces of wood up to 17 inches long. I am pleased with the heat output, though it is less than the Jotul we had (about 15kW vs 22kW). You will get more heat without the wetback attached. I'm sure it uses less wood, though it prefers the wood cut a bit smaller than other burners. We have pine, eucalyptus and wattle trees in the back paddock that we burn after drying for 1-2 years. Main thing is to burn the driest wood first and you'll get the most heat output.

Re: Pyroclassic IV wood fire

Posted 17 Jun '14 12:13 PM

Hi just thought i would give you our experience of our Pyroclassic. Its now into its third winter. we have been through 8 knobs - they burn all the time. the over air tubes have been replaced . the front guard has just been replaced . The wet back has cracked in between the back and the fire box . When we had to pull it apart to have the wetback repaired we were horrified to see how much soot/smoke grit was sitting all around . we only burn last years dry timber and its very dry.

we tried Blue Gum , Macracarpa and this year pine - all ok But the pine wont burn over night 11.30 to 6.30 am - But the fire is still warm in the morning . and it only takes a rake over and a bit of thin stuff to get going again.

all the wood merchants only sell Chunky stuff down here so you cant get a lot in . when you change the air tubes the over fill bars get removed and you can get a bit more in !

as a heating engineer the 12kw claim is way over the top, but to honest all wood fires are .

The wetback claim of 3.6kw is about right . our wet back heats a air heater coil in the roof that is ducted into all the rooms and it does spread the heat around.

We live in a 220m 1904 villa with 3.6 studs , down in Dunedin . and it is on for 7 months . we use about 13 cubes of wood a year .

The air slide is only shut at night and most of the time its between half and fully open , otherwise the heat isnt that great . with a few modifications to the design and updating this could be a stunning heater. wish we had gone for a wood burner with a underfloor air supply like the metros . and for 22 kw the fire needs to be a larger tube . I have a spare pair of over tubes that are about to go in . rather than a hole at the end im thinking of drilling a few holes along its length and blocking up the end- similar to the woodsman idea .

Has anyone tried a basket inside using wood pellets ?

Re: Pyroclassic IV wood fire

Posted 02 Jul '14 07:16 PM

My response would be sure if you want something that looks pretty but doesn't get hot then go right a head and waste your money! Ours went in just after easter, eight weeks later we were unable to light it due to the smoke coming out the front- the flue was compleyely blocked with soot and creosote- the fire has been burning almost continuously since it was out in and the heat output- meh. Creosote started running down the flue after about the first week and the flue is now black with creosote running from every joint. Pivot stoves response to our problems has been "its your wood" water running donw the flue and entering the bedroom - its the wood. water running down the inside of the flue and boiling on the hotplate- its the wood, unprecedaented build up of creosote escaping from he flue- its the wood. The wood we are burning is pine, gum and native stacked for 6-12 months- and hey get this ourt neighbour is burning EXACTLY (and I mean peices off the same logs) wood in his masport and has to have the windows open to cool the house down) while I have to sit on top of ours or my fingers go numb. Our installers have been out several times and fiddled about to try and fix the flue but neither they nor us have been able to get ANY support from pivot stoves (its all our woods fault) So save your money and buy something that doesn;t require feeding with kiln dried wood in order to keep it working

Re: Pyroclassic IV wood fire

Posted 05 Jul '14 11:04 PM

Same here. Room full of smoke today. Flue blocked for second time in 2 years. Its sunday so nobody available to clear it. Doesnt seem to be any way to even partially clear the flu myself so a cold 24 hours ahead. Had issues with water pouring down the flue and on to the top. Leak now fixed but wonder if it contributed to a 'damp wood' effect. Otherwise I'm really happy with it. Appears to be low emissions. Good heat and keeps house warm overnight. If i cant sort the flue issue will be really p***** off.

Re: Pyroclassic IV wood fire

Posted 06 Jul '14 01:44 AM

interesting to hear someone else has had flue issues- pivot stoves are not interested in providing any support at all- they refuse to believe that the problem is anything other than the wood we are burning. Quite frankly their service sucks as much as the fire! It is now (a week after having the flue swept) putting out virtually no heat- I'm guessing the soot build up on the heat exchanger is the problem- I had to have the door open (like you're not supposed to ) in order to feel any heat from it at all this morning. We are going to have it removed and a proper fire put in- the sooner the better as far as I am concerned- I really wanted to like this fire, we bought it as an investment for the house instead it has turned out to be the most expensive paperweight ever. For the approximately 4 weeks when it was working properly it was ok- not stunning but ok. I think their advertising is misleading, they gloss over the fact that the flue is too narrow for some applications and I wonder how many others have the same problem but are fobbed off with the wood too wet story?

Re: Pyroclassic IV wood fire

Posted 06 Jul '14 01:49 AM

see my posts below but I think it's using more wood than our old fire- this is only subjective on the size of the woodpile compared to my memories of last year. However, it is lit pretty much 24/7 so a bit more use could be expected- that said you basically HAVE to keep it going 24/7 as it is a swine to light from cold-which is not helpful if you are out at work all day

Re: Pyroclassic IV wood fire

Posted 06 Jul '14 05:23 AM

I will check with a chimney cleaner about the state of the flue in my pyroclassic. I don't get a smoky room but do wonder about the airflow through the burner. It doesn't seem as good as it used to be. Dry wood is critical to the efficiency and ease of operation of this type of burner and I notice burning my seasoned dry gum the fire is a lot hotter, but also chopping the pieces of wood into bits that are 2-3 inches in diameter helps, at least initially until you have a roaring blaze, is advisable. The instruction book that comes with the log burner emphasises the importance of dry wood. Problem with getting it really hot is scorching of the door knob, which is a design flaw.

Re: Pyroclassic IV wood fire

Posted 06 Jul '14 08:47 AM

Our wood dryness is within their spec but is it reasonable to specify wood dryness that is not available most of the winter. Our only option is to buy now for next winter. We dont have room to dry all that wood.

Re: Pyroclassic IV wood fire

Posted 06 Jul '14 09:41 AM

Hi we buy 13m the year before . I have made a lean too that is sectioned into 4, 3m sections . as we use each 3m section I then buy dry wood and restock for next year.

a few people I know have bought osbourns and been very happy .

I was chatting to a realestate guy yesterday and his friends have one . modern small house and they have no issues . and it doesn't use much wood. I think many of us that have large houses in need of serious heat energy are swayed by the wood efficiency statement, saying they don't use much wood , at the end of the day , large amounts of heat require large amounts of wood !

I think the underlying thing with Pyro is . Don't expect to heat what they say . in a modern average size 120m home with 2.2 stud and good insulation all round they fantastic , saying that a 8kw heatpump would be !

Re: Pyroclassic IV wood fire

Posted 24 Jul '14 08:12 AM

I got excited to view Pyroclassic's website, after having seen the woodburner in the shop, and growing up in Europe with wood burners which were hot for days, and large and fantastic, this pyroclassic is my first choice.Why going for anything else? But now I am unsure. We will build a very small house, i.e. 60m2 or so, and we more worried that it will be too hot in there, since we will insulate well too, plus having passive heat with perfect sunny aspect. Would love to hear from somebody who uses pyroclassic in a small new house, and would love to hear more about this problems of water running down too. We only burn, as we learnt over seas, 3-4year old wood, which was SPLIT 3 years plus, not just stored in large logs. so should be fine with moisture contents.

Re: Pyroclassic IV wood fire

Posted 27 Jul '14 10:02 PM


We have a 200 square m modern house built in 2007 in Pukekohe that we installed a Pyroclassic fire into a couple of months ago.

As a disclaimer I used to work for a well known NZ wood fire and Gas Distributor in a Technical role.

Ok the Pyroclassic fire has heated our house very well indeed. We have a 7kw heat pump in our living area and we haven't used this since the fire went in. I went for a Pyroclassic as I like the design and while the emissions figures are a bit overstated as all wood fires are I believe the fire is relatively low emission and I also believe the efficiency claims. We have run the fire pretty consistently for 18-20 hrs a day since it was installed and we've burnt about 4 cubes of wood so far. This has been a mixture of pine, and Macro... While not every bit of wood has been under 20% moisture content the majority has been.

We had an issue with the fire back puffing smoke into the room on a couple of occasions. I shot down to M10 and grabbed a set of flue brushes and swept the flue and this cured the issue straightaway. Having said that the flue was in no way blocked, there was a minimal bit of build up. I also looked at the installation of our flue and despite using the standard flue kit the install wasn't compliant to AS/NZS 2918. Tis states if the flue is within 3m of the apex of the roof the flue needs to extend 600mm above the apex. I cured this by fitting a bit of 100mm SFP SS flue pipe to the top of the existing install and this has now cured the intermittent back puffing as the flue now has good draw and exits into clear air above the roof.

Fire performance has increased as a result. I'll nip back up on the roof in a couple of weeks and see what sort of state the flue is in.

My view on flues running with creosote etc. would be that to get creosote formation occurring either the fuel is damp so the combustion is cool or the combustion of the fuel is incomplete leading to lots of smoke which then cools and forms the creosote. I wonder what length of flue is being run???

All manufacturers of wood fire overstate their max heat output as the standard Testing they all have to undertake results in a very low figure which they don't like using so they either run the NZHHA test, or run a calculation based on wood energy content and fire box size...

Overall I'm content with the Pyroclassic it is an interesting fire to own...

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