Walltherm Zebru Gasification Fireplace experiences.
- Thread starter scooby074
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
![[Hearth.com] Walltherm Zebru Gasification Fireplace experiences.](/talk/data/attachments/167/167797-bed689a179e228e91eb9cd14e8aa4486.jpg?hash=qSukas1Yob)
Looks like it came right out of a brochure!
I've been intrigued by those units. You'll have to write of your experience after some time goes by.
I've been intrigued by those units. You'll have to write of your experience after some time goes by.
Karl_northwind
Minister of Fire
all over germany and austria I saw wood stacks of 1 meter long wood. I couldn't figure out what they were burning it in (knowing a bit about the euro gassifiers) but found out that they cut and split in 1M lengths, for easy stacking, handling etc, then buck it into 1/2m (19") or 1/3 M (13") lengths for inside storage and burning.
I have a Walltherm stove for four years. It is quite difficult to keep the stove burning properly and over the years it has become worse. I think I have now identified the problem as being the rear flue passages. The cleaning brush will go to the bottom but it doesn't clean them properly. I have been using wood briquettes which makes it worse because it leaves a harder coating on the the sides of the flue passages and one is blocked completely. The heat output to water is practically non existent, the fuel is just smoldering away without producing much heat and sometimes the flue gases explode.. I don't know how to clean it properly and I may have to replace it with a more conventional stove.
The draught is generating by preheating the chimney. The flue gases initially go straight up the chimney by setting the bypass lever. When the thermometer on the chimney goes to 300C the lever is changed to the gasifying position and in theory the warm chimney should then draw the flue gases down. to burn in the lower chamber and then up through the flues at the back. In practice it doesn't always keep the gas burning and also if the lever isn't changed in time the fire gets hot enough to burn paint on the flue pipes.
What is your boiler return set at? I tryed to cheat and go with a 55 degree C (131F) mixing thermostat but it's too cold as the flue gas is too cold for a proper draft. I played with it with a ir gun to watch the jacket temperature and controlled it by turning the pump on and off. Average of 65-70 degree C seems to work so I've ordered a 70 degree thermostat for the boiler protection. I will see how that works when I get home from work in 2 weeks.
You would think you could run a discharge pipe off the pressure relief valve to the outdoors.
The stove came with a faulty thermostat, it is 10 degrees out so I have to set it at the maximum 70C to get a return temperature of 60C. It is probably part of the problem, another ten degrees might help but part of the problem is that the flames don't reach the bottom of the flue ways as they would in a normal stove.
How tall is your chimney? What is your flue gas temperature? The manual says that 60 degree return temp is absolute minimum and it also says to run in the 60-70 range. I have a 24 foot 6" chimney but since I put it under my stairs it has to go through two 90's and 18" of horizontal and form my understanding that significantly reduces draught. So running a hotter boiler temp produces a hotter flue gas which provides an adequate draught for my stove. Flue gas is around 145 and it's working good.
The chimney is not very tall because it is a single storey building. I extended the chimney with a pipe on top but it didn't make much difference probably because the house is in quite a windy position.
Very interested to know how you are all making out with the Walltherm units. Dhaslam you seem to be having trouble and are therefore not happy with your system. Gkingsley yours was new and you seemed enthusiastic about its potential. Has it lived up to your expectations? I am considering this unit to partner with a propane boiler to heat a new 6000 ft home in Ontario Canada. I don't think that this unit is sufficient to heat the house alone but I want some sort of log burner in my basement and this seems like a useful alternative to an ordinary stove / fireplace.
Passion do you still have access to the Walltherm units?
I designed my house heating around one of these units. I just talked to PSES to order and they told me they are out of stock and no longer going to be carrying them and I haven't been able to find anyone else yet who sells them.
Similar threads
