Milan insert vacuum problem

[toolcrafter802]

We are running an Enviro Milan fireplace insert. It is vented through a flexible stainless pipe connected to 6 inch stainless chimney liner. We have recently had trouble with lazy burn and pellets building up in the burn pot. We have broken down the stove and done a thorough cleaning and cleaned the venting pipe and the lowest part of the chimney liner. We are still having trouble. The vacuum will not go above 10-12 on our magnahelic, 14 is spec for this stove. So, two questions: 1. How often does the chimney liner need to be cleaned when running a pellet stove? ( Ours has not been cleaned from top to bottom for a while) 2. Could the air intake on the back of the stove be affected somehow or what else can affected the air intake if that is clear of blockage? This stove was running great up until last week.

Thanks for any help with this.

 

[SmokeyTheBear]

The termination cap could be filled with crud that would do it, very rare for there to be build up in the vertical portion of the venting.

The flexible portion can cause this problem if there is a loop that sags downward after the stove.

A failing combustion blower motor as well did you get this when you cleaned? The cavity it is in and the impeller can build up ash and cause this problem.

 

[imacman]

.....We have recently had trouble with lazy burn and pellets building up in the burn pot.

I know you said you cleaned the stove, but the symptoms you describe are classic "dirty stove syndrome".

Was the stove pulled completely out, and both blowers removed & cleaned?

If there are ash traps on this stove, have they been opened and a vacuum with a small rubber hose used to snake all around inside?

The back brick panels should be removed and a small hammer or mallet used to "bang" on the back wall to dislodge hidden crud.

Are you POSITIVE the air inlet is clear? Do you have an OAK connected to the stove?

 

[toolcrafter802]

Update:

The stove had been thoroughly cleaned on interior, ie. pulled firebox panels, etc. We pulled out stove and cleaned the back to make sure air inlet was clear and blower motors were dust,crud free. Also dropped a brush from top down through the chimney liner and cleared ALOT of accumulated fly ash. Reconnected the stove and we were very happy to see the magnahelic run up to 30 or so at the start. Closed down the damper and it is running well again at 14. So ,I guess we answered our own question about the chimney liner. We'll run a brush through once a season from now on.

Thanks for all the advice!

 

[nailed_nailer]

toolcrafter...
Most of us try to do a "deep clean" about every ton of pellets.

Deep Clean involves
removing both blowers and cleaning them.
Clean/scrape vent path from firebox to appliance adapter on rear of stove.
Clean out the fly ash behind fire brick/fire box lining
Clean out the Air supply (OAK)
Clean out the "clean out T" at bottom of vent.
Scrub the vent path with a brush.

Lots of folks also use the leaf blower method
Do a search on here for Leaf Blower Method

This is in addition to weekly quick cleans.
Scrape burn pot
scrape heat exchangers
vacuum out firebox ash
Dump ash pan
Clean front glass.

Good Luck,
---Nailer---

 

[imacman]

toolcrafter...
Most of us try to do a "deep clean" about every ton of pellets.

Deep Clean involves
removing both blowers and cleaning them.
Clean/scrape vent path from firebox to appliance adapter on rear of stove.
Clean out the fly ash behind fire brick/fire box lining
Clean out the Air supply (OAK)
Clean out the "clean out T" at bottom of vent.
Scrub the vent path with a brush.

Lots of folks also use the leaf blower method
Do a search on here for Leaf Blower Method

This is in addition to weekly quick cleans.
Scrape burn pot
scrape heat exchangers
vacuum out firebox ash
Dump ash pan
Clean front glass.

Good Luck,
---Nailer---

Yep, what he said!