A Hybrid, a Cat Thermometer, and some questions on the magic number: 500 Degrees

[LibertyRansom]

Hello! I had a Lopi Evergreen NexGen-Hybrid Insert installed last week. It has a temperature probe going to the CAT. The manual says the CAT should not be engaged until warmed and you can tell when it is working at 500 degrees. However, I have several questions I couldn't exactly find answered on the forum:

• I burn somewhat smaller fires. Notably, once the probe reads about 350-400 degrees, I engage the CAT, and, as a result, the temp climbs to above 500 degrees within about 90 seconds. Is this an OK procedure?
• Should I disengage CAT once we are below 500 degrees? Typically, the CAT probe will reach around 700 degrees, then slowly drop to below 500 after several hours. Notwithstanding, even though the CAT is below 500, I'm still happy with the room temp, and may not add logs for a few more hours.
• Despite loss of efficiency, is it OK to run the Hybrid with CAT bypassed? Notably, the advertising material states "This advanced system drafts and operates like a super clean non-catalytic stove ..." Notwithstanding, the manual indicates the bypass is connected to both CAT and secondary burn tubes. (Note, there are some errors and contradictions in the owner's manual I noticed ... so this somewhat not reassuring)

 

[kennyp2339]

So if your getting secondary flames your firebox temps are around 1,150 deg f to put that in perspective. Why not do a few runs with a loaded firebox and leave in cat mode to test the waters?

 

[begreen]

Why are the fires typically so small? Is the stove oversized for the area?

 

[LibertyRansom]

Below is my prior post on room size. Long story short, I've only had it a week, the fires have been small because weather has been 40 to 50 degrees outside, so not much heat is needed.

I think the room size actually works out decently. If the fireplace room is 80, the dining room will be 74, and the split level upstairs (far away) is around 68. This is only with the attached Fireplace Fan. Map at link below:

Lopi Evergreen too big? Fireplace in a small room within a big house.

I am strongly considering buying a Mid-sized Lipo Evergreen Fireplace Insert this week for back-up/ancillary heat. However, the room it will go into is only approx. 14 x 19 feet. The ceilings are 7 and half feet. No second floor above the fireplace room, but the house is a split level and...

www.hearth.com

 

[begreen]

Yes, now I see. These temps are so unusual for Buffalo in December but the question makes sense. We are also having a very mild winter. Some of the daffodils are already 5" tall and the hazelnut trees are in full bloom. This is why we have the heat pump. The stove doesn't get lit until it's below 45º. Try to burn short, hot fires and let it burn out. You don't have to bypass the cat when it naturally drops below 500º toward the end of the burn.

 

[LibertyRansom]

Yes, now I see. These temps are so unusual for Buffalo in December but the question makes sense. We are also having a very mild winter. Some of the daffodils are already 5" tall and the hazelnut trees are in full bloom. This is why we have the heat pump. The stove doesn't get lit until it's below 45º. Try to burn short, hot fires and let it burn out. You don't have to bypass the cat when it naturally drops below 500º toward the end of the burn.

Ha, yes, a year ago from Today we had a killer blizzard and temperatures of 0 degrees! It was unreal. I certainly don't' miss that, but my wife and I are really looking forward to getting good use out of the stove, and could not wait to fire it up. I appreciate your insight.

However, regarding the last question, I am still curious whether there are any meaningful risks (aside from low efficiency) in bypassing the CAT. Not that I intend to (I want efficient fires!), but for example, if I need to start it up and don't have time to baby-sit it for 20 minutes for it to get warm before engaging, so I just set it and leave it ... or several years in the future the CAT crumbles and I'm delayed in replacing it...so I just run CAT bypassed for a few months. I've read differing threads that it depends on the stove...

 

[hoot]

I just did my first fire yesterday in my Lopi Large Flush Hybrid.
What is interesting is in the manual they do not tell you what temp readings are too high. Like the OP said, it tells you 500 deg is where the CAT begins burning smoke.
The only reference to overfiring is if you see metal turning red.