What are some reasons a stove kicks out a weaker flame?

[jbrogley]

When it was 35 below we just turned the stove off and closed up the room. When it's not heated that room drops to almost the same temp outside (sunroom...way too many windows). I started the stove up tonight (it's about 20 degrees out) and it's been burning an hour and a half and the stove is just okay...I can still touch all parts of the stove and the air being kicked out isn't that warm.

I truly think I've cleaned it out nicely. And I've read the manual. It makes no mention of weak flame in the manual.

What are some reasons for a weak flame?
When a stove is that cold, does it just take THAT long to warm up?

 

[webbie]

I can answer the second part. It takes the air and the walls and the floors, etc a LONG time to warm up in that weather. I use a pellet stove in my shop, so I tend to start it from scratch when it is very cold in there. For many hours afterwards the air comes out fairly lukewarm. The reason for this is that the air GOING IN is freezing. This is the concept of "temperature rise" that I tried to explain in another post here. This means that, for example, the pellet stove may heat up air going through it 25 degrees. So if the air going in is 50, the air coming out may be only 75, which feels quite cool (that is the temp of most air conditioned rooms). But once the room temp gets up to 65, then the air coming out is 90.

These numbers are just guesses, the actual rise is probably greater, but the theory still holds.

A weak flame, if that is truly what is happening, could have many causes....or a combination of more than one.

The vent or heat exchangers - both in the stove and the piping.
the burn pot not being properly positioned
and even the blower or controls.

 

[buildingmaint]

So why have an outside air kit installed ? If inside air is better , and easier to heat ?

 

[webbie]

Good point, but a properly designed stove would not use the outside air to send back into the room - only to burn the pellets. I think that is how the better designs work.

If a stove pulls the regular blower air from the outside - that would cause terrible total efficiency in colder climes.

 

[jbrogley]

We draw air from the outside...so the air outside is 20 degrees TOPS. The air inside is the same. So it's probably just taking forever to warm up ("I think I can, I think I can!"). We'll watch it. The room is warming up, but we're going on the 3rd hour...oh well...it's okay.

 

[webbie]

Again, keep in mind that the pellet stove uses two sources of air

1 for the burning of the pellets - combustion air - from the combustion blower
then then some for the convection blower- the room air blower

In most stoves, the outside air only feeds the combustion blower, so that cold air gets burned and goes back outside.

The other blower takes regular room air, warms it some, and then returns it to the room.