Review of Jotul F 400 stove
Airwash disappointing - efficiency high.
I have owned, used, supplied and installed every single Jotul traditional cast iron stove from the F100 to the F600. Some of my customers who have purchased the F400 have complained about the glass not keeping clean. Initially I put this down to poor quality of wood, draught issues or simply the inability of the user to operate the stove correctly. However, to get to the bottom of this I have now tested this stove extensively.
The stove is generally well made perhaps with the exception of the ash pan door assembly. The door to access the ash pan hits the ash lip when trying to open it. This is a manufacturing fault due to the hole which houses the hinge pin not being drilled in the correct angle through the casting, so sadly it is not rectifiable. However the door does seal well, so if you don't mind lifting the ash lip a little bit to avoid contact you might not be to worried about this. The only clear fault of this stove is the air wash or lack of. In the UK the F400 is supplied with two different inspection cover plates which regulate the amount of air that is either diverted straight into the fire or through the side channels of the stove into the air wash system. The so called USA plate is installed when the stove is supplied and the EUR plate is supplied with the stove (presumably for use in Europe based on the assumption that we burn smokeless fuel instead of wood). These plates supply air directly to the fuel (similar to the primary air flow on a multifuel stove supplying air through the grate). If the EUR plate is used a far greater amount of air will flow directly to the fire rather than through the air wash system, which means the glass will not stay clean. So the obvious choice if you want to burn wood is to keep the USA plate in place (which only has two small holes of about 9mm each instead of the large centre cut out of the EUR plate which is about 40mmx9mm thus resulting in a much greater flow of air directly to the fire and therefore weakening the air wash) The USA plate will greatly improve the air wash dilemma but not cure the problem entirely. The reason for this is that the stove will still draw a very significant amount of air through the clean burn system (a sheet steel plate with more than 80 holes which is bolted to the cast iron baffle plate) The air is supplied to this arrangement via both side chambers and can not be controlled. A previous reviewer described the 'running away' scenario. This is down to the lack of control over the clean burn system. Even if you try to shut the stove down completely by moving the lever to the left the stove will still continue to burn fuel because of the constant air supply through the clean burn system. This supply of air to the clean burn system weakens the air wash by definition. (if all the air is supplied via the air wash rather than just 50% you will have a stronger air wash) This is typical of most stoves using an afterburn/clean burn system where air is lowered onto the fire but in the case of the F400 the ratio between air supplied through clean burn and air wash is in favour of the clean burn i.e. weakening the air wash and resulting in a dirty glass. On top of this the F400 has a very large/wide glass frontage and this compounds the problem of keeping the glass clean. Testing has revealed that if the clean burn system is disabled (easy to achieve but not recommended) the stove is completely transformed; the air wash works perfectly fine keeping the glass clean (apart from the very outside edges) and control ability of the stove is greatly improved. However, this is not how the stove is supplied and can therefore not be recommended to users. So if you don't mind the glass becoming dirty and obstructing the view of the flames you are getting a well made stove with classic design features. The firebox is of generous proportions and will accept logs of 500mm. The efficiency if very high at 84% The F100, F3 CB, F500 and F600 don't suffer from this problem to the same extent.Stove expert replied: Very disappointing on a stove that is well known, this customer seems to have tried and tested several so perhaps a modification is in order!!
- Show oldest comment first
- Show newest comment first
- Sort by most recommended
Chris Cook said 11 years ago:
I would very much like to get in touch with this reviewer, having discussed issues with the manufacturer. It sounds like he would be really helpful to tell me how to modify out f 400