Alaska 140 Dual Burner - Moisture in Hopper

It got down to -16 here last night! I started my second burner and everything is running fine. Draft is correct (-4). I woke up this morning to lots of moisture in the hopper. Two CO detectors in the house both read 0 ppm. What else could be causing this moisture?

How is the draft over the fire? (combustion area compared to room)

Rob,

Don't know about the draft over the fire. I take my draft readings from the pipe as it exits the furnace. How would I go about checking over the fire?

Thanks.

The moisture on the underside of the hopper lid is an indicator that some exhaust is finding its way there due to more combustion air coming in than can be exhausted out the flue. If your air setting on the combustion fans is the same as it has always been and you never had the problem before then you should look for fly ash blocking the exhaust. If this is your first time ever using both burners, you may need to cut the combustion air being fed into the burners.

I don't have a 140, but the note below mentioning where other 140 users check their over fire draft came from this thread... Alaska 140 Hopper Stink?

"If your stove is close in design to my 140 dual feed that is probably the same hole I used to check my over fire settings .

The hole on my stove is located above and to the right of the flue and measuring from the floor it would put it about 6" above the top of the ash door."

Ok....so I'm a little confused on the draft. I have the manometer permanently installed in the stove pipe just as it exits the stove (about 8 inches out) and my draft stays at .04 with both burners running. Is the draft inside the box going to be different than this? Do I need to monitor in both places?

Thanks for your help.

I believe the draft measurement would be more at the flue, rather than "over the fire" in the fire box. It depends on your manufacturer's suggestion as to where you need to measure it. For Keystoker kokers, the draft measurement of .025 needs to be "over the fire", with a hole next to the ash pan door.

bchapman wrote:Ok....so I'm a little confused on the draft. I have the manometer permanently installed in the stove pipe just as it exits the stove (about 8 inches out) and my draft stays at .04 with both burners running. Is the draft inside the box going to be different than this? Do I need to monitor in both places?

Thanks for your help.

When more air volume is introduced by fans blowing into the fire box than the draft can remove you will find it may read different over the fire...this only need be a small amount and the hopper moisture is your proof. In worse cases CO alarms will sound.

Always adjust blowers so breech always is the higher reading of the two. Anything less and gases back up and will spill over outside the fire box.

Just spoke with a guy at the Alaska company. He seems to think based on my situation (good draft on manometer with exhaust leaking into hopper) that my strongback gaskets may need to be replaced. He said these should be replaced every 2-3 years and I've been burning for 5.

He also said that monitoring the draft in the stove pipe is ok. Not necessary to monitor over the fire.

Thanks for all the help on this. I'll report back on my results.

You're saying strongbacks became an issue because you lit second burner????

That's what the company is saying. Apparently the added combustion gasses and the pressure from the 2nd combustion fan can cause leaks if these gaskets are bad.

I think before I would shut down to replace the strong back gaskets, I would try restricting the combustion blowers a little and see if that changes anything.

Then change the gaskets when it warms up a little. Like this weekend.

I would have the same issue from time to time on my Hyfire II. Sometimes it was from damp coal and running the stove hot.

Rick

Something's not adding up...there is never supposed to be pressure in the fire box...it wants to be always negative...and more-so negative in the breech than in the over the fire draft. This is how you got the moisture in hopper...not enough difference between the two.
Your's is not an extreme case...you are on the very edge, but if chimney draft deteriorates even a little, it will only worsen.

Not saying you would need to constanly monitor over the fire air draft, only initial setup and again anytime you need to change/adjust air input volume for some reason.
With some flexible tube you could move between the two ports.