Smoke coming into the house
- The furnace will smoke during the first fire-up for about 15 minutes while any residual oils and preservatives on the steel are burned off. Also, the paint on the furnace will smoke during the first fire-up. This is not toxic, but it is recommended to open doors and windows for the first 15 minutes of the first firing of the stove.
- If smoke comes out of the air damper at the lower rear of the furnace and/or the front air holes on the front of the furnace – this is almost always due to a chimney issue.
o If this is the first fire-up of the year – perhaps the chimney is still too cold to create a draft to draw the smoke up the chimney.
o If it is an outside masonry chimney – the cold masonry/brick, etc., is very slow to create a draft. This is the least effective type of chimney and is a challenge until the thermal mass has adequately warmed. In some cases, it is necessary to install a stainless steel liner inside the chimney and insulate around this liner.
o If the barometric damper is set on too low of a number, the chimney will not create enough draft to pull the smoke out of the house. Try setting the damper “1” number higher. (for example, if it is set on #3, move it to #4). Avoid making large changes.
o Your home or facility may be too airtight. If there is not adequate combustion air available for the chimney to draw – you will smolder the fire, and smoke can enter the home. Test this by opening a window or door to see if this solves the issue. This can also be caused by a laundry dryer, range hood, or bathroom exhaust fans drawing so much air out of the house that it actually can reverse the draft of your chimney.
o If opening the window or door fixes the issue, installing a fresh air inlet into your home is recommended. This can usually be done for around $20 and is easy to do.
o Check to ensure that the air inlets inside the firebox are free from ashes. These air inlets are just below the door on the inside surface. It is easy to plug these with ashes when reloading the furnace.
o Finally, if you have been burning wood with a previous wood stove that had a tendency to produce creosote – check your stove pipe. When you install a Vapor-Fire furnace – over the first weeks to months, they tend to dry out any existing creosote, and this will fall down inside the chimney and/or stove pipe. This dried creosote can be significant and even fully plug the chimney and/or stovepipe. This will prevent the draft from pulling smoke from the house.
Smoke from the chimney
- When firing up a cold furnace, you will see smoke from the chimney for about 30 – 45 minutes. It is necessary for the furnace to get up to temperature in the gasification chamber before the gases (wood smoke) can be fully burned. Due to the huge mass of the steel and firebrick in the Vapor-Fire, it will take some time for the furnace to get up to temp. Once at full temp, you should no longer see smoke from the chimney.
- When you reload your furnace and you are placing fresh wood into the firebox – you will see smoke from the chimney for 5 – 10 minutes. Again, by adding this much colder wood, the furnace needs to get the gasification chamber back up to temperature to burn the gasses fully.
- If the outdoor temperature is below 32 degrees F, you will see white water vapor coming from the chimney. Don’t confuse this with wood smoke. This should be white billowy vapors that quickly dissipate. Wood smoke is generally somewhat blue in color and tends to flow downward as if it was heavier than air. Above 32 degrees, you should not see smoke or vapor as long as the furnace is at full operating temperatures.
- To produce smoke, it is first necessary to smolder the fire. This means you are starving the fire of adequate combustion air. This can be due to your home being too tight (see notes above about fresh air inlets), or you have your barometric damper set too low to generate adequate draft to the furnace.
Getting white smoke streaks on the front of the furnace
- This often results in a brand new furnace as you are burning off any residual oils or preservatives and, finally, new paint during the first 2 or 3 firings. This can be wiped off with a rag and should not return once the furnace is fully cured.
- If the main firebox door seal is not adequately tight, the door may be leaking, allowing smoke streaks. See our video for the proper way to adjust and tighten your firebox door. The door gasket will take a set and often needs to be re-tightened at about 6 months and then at about 2 years. After that, it will likely be good for the next 6 – 8 years.
The blower doesn’t start
- During the first fire-up each year, the blower will act erratic. It may start and stop repeatedly. This is due to the fact that there is so much cold mass in the furnace that needs to get up to full operating temperature. It often takes an hour or more to get up to a stable temperature each year during the first fire-up. After this time, the blower should operate normally.
- If the low-limit thermostat is mounted on the side of the furnace – it will take much longer for the heat in the plenum to get up to the temperature necessary to activate the low-limit thermostat. The low-limit thermostat is the on-off switch for the furnace. The blower is not controlled by the computer control!
- If the low-limit thermostat has gone bad, the blower may not start. To test – first disconnect the power to the furnace. Next, remove the 2 wires from the low-limit thermostat and connect these two wires together. Tape these with electrical tape to prevent them from contacting any metal and shorting out. Next, turn the power back on. The blower should now run. If it does not start – the low-limit thermostat is most likely defective.
o First, ensure that the white button on the high-limit thermostat is pulled out and on automatic. Sometimes this button sticks, and it may be necessary to first push it in and then pull it out again.
o Make sure the wires from the high temp thermostat are connected to the fan relay. Without these wires connected, the blower will not run.
o Make sure no circuit breakers or GFI’s are popped. I know this sounds overly basic, but I’ve run into this several times.
o If everything else checks out – take a power cord and connect directly to the blower wires in the lower electrical box at the base of the blower. Connect the hot power wire to the black or red wire coming from the blower motor and the neutral wire (usually white) to the white wire coming from the blower motor. Turn the power on, and the blower should run. If it does not start – you most likely have a bad blower motor.
The computer control won’t turn on.
- Make sure that the furnace is not in an “OVER TEMP” condition. In this situation, the high temp thermostat cuts power to the computer control.
- Check to see if you are getting between 20 – 29 volts to the power wires that power the computer control. If you are not getting any voltage – the fan relay is most likely bad and needs to be replaced.
- If the power wires that feed the computer show voltage between 20 – 29 volts and the computer still does not light up – you may have blown a fuse in the computer. Remove the front cover of the computer and pull out the little brown fuse. You can check to see if this is blown by checking for continuity. If you have continuity – you most likely have a burned-out chip on the computer, and the computer should be returned for a rebuild.
- Make sure the high-limit thermostat wires are correctly connected to the fan relay at the back of the furnace. If the high limit is not properly connected – the computer will not be fed with power.
Not getting enough heat to the house
- Start with basics
o Is there a screen or mesh on the top of the chimney? If so – get them removed
o What is the chimney set-up?
- Are there any horizontal stove pipe runs?
- Is the chimney inside the home or on the outside? Outside chimneys made of masonry are quite poor. It is sometimes necessary to line these chimneys with a stainless liner and insulate around the liner.
- Is the barometric damper set at the correct setting for the application?
- What is the wood moisture content? Wood over 28% will use a high portion of the generated heat to drive off the water, reducing the heat available to the home.
- What kind of wood are you burning? Some woods have a very low Btu content, such as balsam. There is just no heat content in the wood.
- If the barometric damper is set on too high of a number, you are drawing too much heat out of the chimney.
- Is the furnace sized correctly for the home?
- Don’t use a restrictive chimney cap. We recommend a chimney hat with no screen, mesh, or restrictions. This is the one we use, and it works great! Famco (Wind Directional Chimney Cap)
o Are the heat baffles installed in the heat exchanger chamber? If you have a good chimney arrangement, this should provide an extra 18% heat for the same amount of wood.
o What temp is the low limit thermostat set at? If this is set at too high, the blower won’t turn on until this temp is reached. Try setting the pointer on 100 or even down to 95 degrees to get the blower to start sooner.
- The Vapor-Fire is a great furnace to maintain a constant temperature in the home or shop. We suggest maintaining the same temp day and night. These are slow to “recover” temperature if you let your house get down to 30 or 40 degrees but are great for providing nice consistent, comfortable heat.
- Is the furnace sized correctly for the application? Or is the furnace too small for the application? Even in these cases, you can often provide 80 – 95% of the heat if you want to supplement during the coldest days with the backup heat source.
- Is the issue with the furnace, or is it an issue with the home/building you are heating? How well is it insulated? How good are windows and doors? Is the building tight, or does it have numerous air leaks? A person may have to make some improvements to the building.