Castle Serenity ignition issues... too much air?

[mmcc]

I have a Castle Serenity pellet stove. I have a hard time getting it going, but once it is going it runs fine.

The igniter isn't working so I've been lighting it with some starter gel and a burn pot full of pellets.

I think there is too much air going through the pellets during its start up process. When the start up fails, it seems like it is due to the pellet feed rate being inadequate to keep up with the burn rate.

I have about 5' of 3" PelletVent going into an existing 6" chimney that was previously used for a wood stove. My guess is that there is inadequate back pressure to keep the air flow rate low enough.

I've lowered the exhaust voltage for Stall 1 as low as it will go (I assume this is what is used during the start sequence, but I don't know for sure) and this hasn't helped. I seem to have the best results when I run a space heater on the same circuit as the stove when it is starting up - I can audibly hear the blower slow down when the space heater is on.

Any suggestions for how I might might the start up more reliable?

 

[Ssyko]

What is the total length of the exhaust for the stove?

 

[mmcc]

What is the total length of the exhaust for the stove?

Total length is about 17'
I'm going to amend my estimate of 3" pipe - there's about 7' of 3" pipe and about 10' of 6" pipe.

The colder it is in my shop, the less likely it is to successfully ignite and run. As cold air is denser than warm, I think that supports the "too much air" theory.

 

[Ssyko]

That about as close as a pellet stove will go. What does the manual say for venting?

 

[mmcc]

I just reviewed the manual (which I found here for future reference: https://images.thdstatic.com/catalog/pdfImages/6e/6e2ee81f-71b6-4539-b354-7bc6d4aba9ff.pdf)

I don't see anything about a minimum vent length.

On page 12 it says "Total length of horizontal vent must not exceed 10 feet. The maximum recommended vertical venting height is 18 feet.", and it has a diagram on page 18 for a "Class A Chimney Retrofit", which reflects my installation pretty closely.