E Codes

Vacuum loss: Pellet stoves require a clean, unrestricted flow of combustion air to perform safely and efficiently. Vacuum loss can occur if any of the following circumstances exist:


The exhaust setup should be done in such a way as to keep the horizontal length to a minimum, (See Installation Page) too long a horizontal run will slow the air flow down to a point where vacuum loss can occur. This is caused by a lack of natural convective rise in the horizontal section which means that the exhaust blower has to physically move this exhaust without the help of this natural rise. Two to three ft. of horizontal will generally work. As for the vertical portion of the installation; it is mandatory that the vertical must be at least 3' but it can be run higher. In this case, if the installation will require more than 15 ft of total pipe for the exhaust run, the pipe diameter should be increased to a 4" diameter at the 15 ft mark.
B. The unit is designed to handle a standard through the wall pipe kit which contains two 90 degree elbows. One of which is a "clean out tee" which is placed at the bottom of the vertical stack to allow ease in cleaning of the flue pipe itself, and the other is generally placed at the top of the vertical to turn the flow of exhaust away from the structure if the flue is not being run above the roofline, before attaching the horizontal cap. Additional 90 degree elbows to this system can add resistance, or back pressure, to the flow of exhaust which could compromise the free flow of air needed for proper function. For "catty corner" installations an additional elbow is used. This elbow would be a 45 degree and would provide much less resistance; therefore addition of this piece would generally not compromise airflow.
C. An Outside Intake Air source is Mandatory with all freestanding England's Stove Works' pellet units! As stated above, the free flow of air through these units is extremely important to ensure proper function. Virtually any structure into which a pellet stove would be installed will not have enough draftiness built into it to allow for the amount of air to leak back into the structure at the rate a pellet stove will remove it, the size of the structure is not a factor in this; therefore, a buildup of "negative pressure" will occur as air is removed from the structure. This buildup would then restrict the free flow of combustion air through the unit and will cause a loss of vacuum.  Improper installation of the outside air intake can also cause vacuum loss; the unit is designed to be connected to a 2" intake pipe which should be installed in as short and direct a manner as possible. This pipe would have to be less than 6 ft. in length and may not contain more than two 90 degree elbows. If these parameters cannot be met, the diameter of the intake must be increased to a 3" pipe for the entire length of the intake run. Most basement installations would have to be done in this manner. (See Basement Installation Page)

The intake pipe should be equipped with a screen to keep any animals, bees or foreign material from getting into the intake, but the screen used should not be restrictive in its makeup, and should be installed above the snow drift line in areas where this could be a problem.

D. Vacuum loss can occur at higher elevations due to the air being thinner, installations above 4,000 ft above sea level should be done using a 4" pellet vent pipe rather than 3" and intake should also be done in 3" in most cases.
E. Failure to properly clean and maintain the unit can cause loss of vacuum to occur. Proper airflow will not be attained if the unit is not cleaned out regularly. Areas that must stay clear are:
  1. The firepot itself, especially the area under the wear plate, must not be allowed to become blocked. This area should be cleaned out at a minimum every few days or daily if the unit is being run on higher heat ranges.
  2. The impingement plate (or baffle plate) should be removed weekly and all areas behind it should be thoroughly cleaned.
  3. The heat exchangers, which can be accessed when baffle plate is removed, should also be thoroughly cleaned.
  4. The flue itself (the pellet vent pipe) should be cleaned monthly or after every ton of pellets (whichever comes first).
  5. The entire stove and flue system should be fully cleaned and serviced annually. Failures due to neglect in cleaning or maintenance will not be covered under warranty! It is recommended that an ash removal system be utilized to perform cleaning on these units, contact your hearth retailer or England's Stove Works to obtain such a system.   (See Cleaning Page)
F. Other possible causes for "E" would include; non functional exhaust blower, a loose wire from the flue blockage vacuum switch to the control board (these wires connect to the control board near the bottom of the board), a loose hose connection from the flue blockage vacuum switch to the exhaust chamber, a blocked connection where the hose connects to the exhaust chamber, or, an improperly positioned baffle plate which would allow exhaust to bypass the top of the heat exchanger, i.e..  If the baffle plate is not positioned flat against the back wall of the firebox at the bottom allowing the fire to get behind it, (this would cause higher exhaust temperatures that could damage the vacuum hose or cause vacuum loss due to lack of air density (the hotter air gets the less dense it becomes, this makes it much harder to sustain vacuum pressure)).
  1. Using alternative fuels such as dried corn or cherry pits, which tend to feed faster, have different burning characteristics and Btu outputs. These fuels tend to burn hotter, and in the case of corn, the kernels burn slower than pellets do, so they can build up in the firepot and cause the fire to become hotter than it is supposed to.

If you have any further questions or concerns, please contact Customer Service at:

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Revised:  11/07/2008

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