Leyden problems, I'm stumped...

[BWT]

Hey Everyone, I'll get right to the details and explain what I'm running into.

- 5 yr old Lopi Leyden professionally installed
- Live in Northern Wisconsin
- Have the unit cleaned annually
- Never had a problem with burn temps or burn time until this year
- Gaskets are in good condition
- Checked for leaks around door, top lid and ash pan and it's a good seal. Checked where top mounts to body and no leaks there either.
- Adjusted the back bypass lever for a snug fit (seals feel good there as well, can't visually inspect)

Here's what I'm running into. For the first 4 years of operation everything was flawless. I'd bring the temp up to 500-600 and close it down tight. Flame would die down and I'd get a nice hot, consistent burn hovering around 600 +/- for 6-7 hours and would still get heat for an additional 2-3 hours (total burn time of around 8-10 hours) when I loaded it full (usually 5 logs averaging 4-5" diameter).

When the stove got up to temp and I closed everything down, the flame would have a small slow flicker with the occasional 'burp' . It was getting enough air to maintain and burn clean, but not burn out of control. If I let the fire actually go out, there would still be nice chunks of what I call 'Black Gold' (aka charcoal lumps) that made re-starting again very easy.

This year, the stove does not seem like it's choking the fire down enough and it burns much hotter than normal. If I shut everything down around 450, it will still continue to climb up to 750+ and cook us out. The flame does not die down like it should, and when it burns down, it completely burns down (no coals left). Average burn time this year has dropped closer to 5-6 hours. I've only been loading half full as I don't want it to get away from me (which explains to shorter burn time, but not why the temp climbs so much after shut down).

I'm a bit stumped. Logic would say that there's an air leak somewhere but I've checked and re-checked using smoke (looking for suction around the seals), dollar bill test on the doors, etc. Everything is a snug fit with no smoke being pulled in through the seals. It almost seems like the air control lever isn't closing all the way but there seems to be full travel pulling it in / out.

Just to make sure I'm getting the terminology correct for the areas I'm referring to, I've attached a diagram. below.

I've checked all the key areas but I'm obviously missing something; air has to be getting in somewhere :-/ Is there another area on the stove I should be checking?

Something I'm wondering is if the small swing plate attached to the air control arm in the back / bottom of the stove is attached with a nut that could back off from heating / cooling allowing the plate to sag and not fully cover the intake? The area is covered with heat shields and I'm not able to inspect without taking things apart. Any suggestions?

Thank you in advance!

 

[begreen]

Have you inspected the combustor refractory assembly? It sounds like it may be breaking down. Do this carefully, it is fragile.

 

[BWT]

Have you inspected the combustor refractory assembly? It sounds like it may be breaking down. Do this carefully, it is fragile.

Thanks for the reply. If you're referring to the ceramic thing that you see when looking into the stove, I replaced that new last Fall along with the 2 side pieces. Worked great for the rest of the year. I have not inspected it this year, but it does not show any signs of visible damage.

I did notice this morning that one of the side pieces is cracked, but still intact. I'm sure when I remove / replace it will fall into 3 pieces but until the replacement comes in I have to leave it in place. Mostly figured this was a type of heat shield and didn't think it could have any bearing on my issue. Would that be correct?

Thanks again!

 

[DougA]

Don't own a Leyden but it sure looks the same as my VC Resolute and I have had the same problems for the last few years but my stove is now 30 yrs old. In my case, the cast pieces have small gaps in the joints. Very tiny but enough for air to get in and cause control problems, even when everything is fully closed. Not sure this will help you but if that's the case, it needs to come apart and be reassembled with new stove cement.

 

[begreen]

I'm not sure. If the wood gas is sucked through a different channel it may disrupt the burn pattern in the combustor. An inspection of the bypass assembly would also be good to make sure nothing is warped and that the bypass closure is tight when engaged.

 

[BWT]

Waiting on a schematic from the dealer showing all the parts I am not able to see without taking things apart. When I get home tonight I'll remove the combustor assembly to see if there's something going on there. The bypass plate appears to be making good contact all the way around with the gasket, but will double check that as well. Will let you know what I find out (if anything)

Thanks!