Quick Hot Fire with Lopi Insert

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Martin D2

New Member
Apr 27, 2024
4
Ont Canada
I spent past winter learning to operate a Lopi Med Flush insert. A work in progress, as I had to unlearn 55 years of experience with conventional wood stoves.
One issue I have is getting quick hot heat from a cold box in the morning. I get a fire started and flames filling the box quickly enough, but the blowers do not start till the thermostat reaches the preset temperature. Depending on the amount, quality of kindling and the placement this takes about 15-20 minutes. More kindling might hurry the process, but I have a limited supply, do not want to waste it. Since the box is full of flame, I would like some of that heat blown out.

The sensor for the thermostat is in the low right corner next to the controls? Building my fire in that corner, rather than the left side as I tend to do could speed up the progress? I am placing wood in E-W pattern.

An extreme measure might be to rewire the fans with a direct lead and a 2 way switch to effect a manual over ride, (after warranty expires). This could have been done by the manufacturer in the first place. Anyone here attempt this?

I am new to this forum, any suggestions, tips would be most welcome.
 
15-20 minutes is quite good. It may take that long to get the firebox hot enough to achieve good secondary combustion. To use less kindling, when starting first lay down two, short, 2" thick "sleepers, loaded N/S about 6" apart. Put some wadded paper and a little kindling in between them. Then put two 3"-4" splits on top of them, loaded E/W, about 2-3" apart. Put a bit more wadded newspaper and kindling in the middle of them. Light this pyre and the fire should take off pretty quickly.
 
Just wish to add to above: If thermostat sensor is in the bottom right corner, would shutting the flue bypass after flames are going well, heat it up quicker? Doesn't seem to make much difference in trial and error.
 
Yes, closing the flue bypass once the fire is burning well is important. The bypass is just for starting and reloading. After closing the bypass, wait a minute or two, then start closing down the air. Closing down the air will let the draft pull more air through the secondary tubes which will aid more complete combustion and a hotter firebox. How much and how quickly the air is closed down will depend on the draft strength. With this insert on a 25' flue in 32º weather, the air might be mostly closed in 5-10 minutes if the wood is fully seasoned. In mild 45º weather, it could take twice as long.

A good source of dry kindling is cabinetry and finishing trim shops and flooring stores. Just be sure to only take unfinished wood.
 
Yes, closing the flue bypass once the fire is burning well is important. The bypass is just for starting and reloading. After closing the bypass, wait a minute or two, then start closing down the air. Closing down the air will let the draft pull more air through the secondary tubes which will aid more complete combustion and a hotter firebox. How much and how quickly the air is closed down will depend on the draft strength. With this insert on a 25' flue in 32º weather, the air might be mostly closed in 5-10 minutes if the wood is fully seasoned. In mild 45º weather, it could take twice as long.

A good source of dry kindling is cabinetry and finishing trim shops and flooring stores. Just be sure to only take unfinished wood.
Thanks so much. Closing the air vent is counter intuitive to me, as I mentioned this stove is a completely new experience. The manual is short on actual operating points. I did obtain quality kindling from a planing mill, but used it all up by Jan. I wasn't able to replace it easily.
 
It is counterintuitive but this is the way that secondary stoves work. In the winter our stove has the air closed down to about 90% and in very cold weather the air is all the way closed while the stove top temp is around 600º. This is on a 20' flue system.
 
I have considered wiring my fan to manual control. Some have a manual/ auto switch that essentially bypasses the thermo disk switch.

Things to consider. Will the air blowing early keep parts of the firebox cool longer and lead to some/more creosote buildup in places that would be bad. Like behind firebricks. I think it’s unlikely especially if you regularly get it up to operating temp. But if you you just do a single small fire every morning in the spring shoulder season it might make a difference.

Lastly I like pine. If you have any it makes great kindling and bigger splits a fast hot fire that will establish a good coal bed quicker than hardwoods. Keeping a good 1” layer of ash on the bottom (higher around the sides and back ) can help insulate the bottom of the stove sending more heat up but it can take longer to get the blower to turn on due to placement. Speaking of placement. You can get magnetic thermo switches so you could move it to a better position carful not to get it to close to temps that could melt insulation.
 
Begreen and EbS-P pretty well covered your questions but for what it’s worth I have the Lopi medium flush as well. It takes more like 30-45 minutes for my fan to kick on from a cold start. I close my bypass once the fire is established, and almost never have the air control wide open. I start out at about 75% open and shut down from there.
 
  • Like
Reactions: begreen