Thread: Boiler direct vent "nuisance" to adjacent home?

New construction residence has installed a direct vent for their boiler directly across from neighbor's path to their front door. Property line is 6 feet (1.8m) from vent. My own research finds that direct vents are excluded from regulations which keep power vents 10' from lot lines (M1804.2.6). However, I'm thinking that the "intent" of this code is to prevent the transport of unagreeable materials to adjacent properties/structures. The following video demonstrates the problem. This is a condensing boiler which prohibits or does not provide a redirect kit. Should this vent be moved, and if so, can it still remain within 6' of lot line? This is in Seattle, Washington.

From the 2012 IRC - not sure what Washington state is using: (bold and underlining are mine)
- G2427.8 (503.8) Venting system termination location.
- - The location of venting system terminations shall comply with the following (see Appendix C):
- - - 1. A mechanical draft venting system shall terminate at least 3 feet (914 mm) above any forced-air inlet located within 10 feet (3048 mm).
- - - - Exceptions:
- - - - - 1. This provision shall not apply to the combustion air intake of a direct-vent appliance.
- - - - - 2. This provision shall not apply to the separation of the integral outdoor air inlet and flue gas discharge of listed outdoor appliances.
- - - - 2. A mechanical draft venting system, excluding direct-vent appliances, shall terminate at least 4 feet (1219 mm) below, 4 feet (1219 mm) horizontally from, or 1 foot (305 mm) above any door, operable window, or gravity air inlet into any building. The bottom of the vent terminal shall be located at least 12 inches (305 mm) above finished ground level.
- - - - 3. The vent terminal of a direct-vent appliance with an input of 10,000 Btu per hour (3 kW) or less shall be located at least 6 inches (152 mm) from any air opening into a building, and such an appliance with an input over 10,000 Btu per hour (3 kW) but not over 50,000 Btu per hour (14.7 kW) shall be installed with a 9-inch (230 mm) vent termination clearance, and an appliance with an input over 50,000 Btu/h (14.7 kW) shall have at least a 12-inch (305 mm) vent termination clearance. The bottom of the vent terminal and the air intake shall be located at least 12 inches (305 mm) above grade finished ground level.
- - - - 4. Through-the-wall vents for Category II and IV appliances and noncategorized condensing appliances shall not terminate over public walkways or over an area where condensate or vapor could create a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment. Where local experience indicates that condensate is a problem with Category I and III appliances, this provision shall also apply. Drains for condensate shall be installed in accordance with the appliance and vent manufacturer’s installation instructions.

Looks like that is a hazard and creates a nuisance - the code only requires a "could" create s nuisance or hazard condition, the code does not require a 'does' create a nuisance or hazard condition.

Originally Posted by Jerry Peck

- - - - 4. Through-the-wall vents for Category II and IV appliances and noncategorized condensing appliances shall not terminate over public walkways or over an area where condensate or vapor could create a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment. Where local experience indicates that condensate is a problem with Category I and III appliances, this provision shall also apply...

Looks like that is a hazard and creates a nuisance - the code only requires a "could" create s nuisance or hazard condition, the code does not require a 'does' create a nuisance or hazard condition.

Thank you Jerry! Yes, Burien has adopted the 2012 IRC and your assessment is very applicable, IMO. There is a dispute over this between homeowners and the city already signed off on the ventilation "as is" last month.

Originally Posted by R Grab

Thank you Jerry! Yes, Burien has adopted the 2012 IRC and your assessment is very applicable, IMO. There is a dispute over this between homeowners and the city already signed off on the ventilation "as is" last month.

An inspection being approved does not indicate that every thing is in compliance and does not approve what is there "as is" - the inspector is, at most, saying that what they looked at was good enough ... it does not mean everything was "looked at".

Originally Posted by R Grab

Thank you Jerry! Yes, Burien has adopted the 2012 IRC and your assessment is very applicable, IMO. There is a dispute over this between homeowners and the city already signed off on the ventilation "as is" last month.

As a continuation of my previous post (I was using my phone for that one and it is difficult to use for a more involved post) I am including additional 2012 IRC sections:

(bold and underlining are mine)
- R109.1 Types of inspections. - - For onsite construction, from time to time the building official, upon notification from the permit holder or his agent, shall make or cause to be made any necessary inspections and shall either approve that portion of the construction as completed or shall notify the permit holder or his or her agent wherein the same fails to comply with this code.
- - - R109.1.2 Plumbing, mechanical, gas and electrical systems inspection.
- - - - Rough inspection of plumbing, mechanical, gas and electrical systems shall be made prior to covering or concealment, before fixtures or appliances are set or installed, and prior to framing inspection.
- - - - - Exception: Backfilling of ground-source heat pump loop systems tested in accordance with Section M2105.1 prior to inspection shall be permitted.
- - - R109.1.5 Other inspections.
- - - - In addition to the called inspections above, the building official may make or require any other inspections to ascertain compliance with this code and other laws enforced by the building official.


- R109.3 Inspection requests.
- - It shall be the duty of the permit holder or their agent to notify the building official that such work is ready for inspection. It shall be the duty of the person requesting any inspections required by this code to provide access to and means for inspection of such work.

Note that R109.1.2 is vague and not all inclusive. Also note that "Other inspections" can be made per R109.1.5.

Keep in mind that the code is a minimum requirement, however, AHJ apply that "minimum" in different methods: some take the code being the minimum as they are to apply it to the minimum extent possible (that is how they interpret "minimum"); some take the code being the minimum as they are not to approve anything less than what is stated in the code (that is their interpretation of "minimum"); other AHJ interpret the code being "minimum" as they get to add or take away things they like or don't like (these AHJ are essentially "making up their own code" as they go, these are the AHJ who can be sued individually as they have now broken the separation between the immunity of enforcing an adopted document and enforcing their own personal wants).

- R110.1 Use and occupancy. - - No building or structure shall be used or occupied, and no change in the existing occupancy classification of a building or structure or portion thereof shall be made until the building official has issued a certificate of occupancy therefor as provided herein. Issuance of a certificate of occupancy shall not be construed as an approval of a violation of the provisions of this code or of other ordinances of the jurisdiction. Certificates presuming to give authority to violate or cancel the provisions of this code or other ordinances of the jurisdiction shall not be valid.
- - - Exceptions:
- - - - 1. Certificates of occupancy are not required for work exempt from permits under Section R105.2.
- - - - 2. Accessory buildings or structures.

- R110.5 Revocation. - - The building official shall, in writing, suspend or revoke a certificate of occupancy issued under the provisions of this code wherever the certificate is issued in error, or on the basis of incorrect information supplied, or where it is determined that the building or structure or portion thereof is in violation of any ordinance or regulation or any of the provisions of this code.

Super helpful! Here are a couple other codes which might exclude "direct vents". However, I believe the intent of these restrictions is met. I appreciate the help you have given me, Jerry, and I understand that the info you give is for guidance only. Could "intent" or other rules be used to enforce either of the following codes for this venting? (BTW I now have confirmation that this IS a condensing boiler with 95% efficiency, CO <100ppm, and manufacturer states vent can not be capped):

International Mechanical Code Section 501.3.1
2. For other product-conveying outlets: 10 feet (3048 mm) from property lines;


IRC 804.3.3
The termination of chimneys or vents equipped with power exhausters shall be located a minimum of 10 feet (3048 mm) from the lot line or from adjacent buildings. The exhaust shall be directed away from the building.

Originally Posted by R Grab

Could "intent" or other rules be used to enforce either of the following codes for this venting? (BTW I now have confirmation that this IS a condensing boiler with 95% efficiency, CO <100ppm, and manufacturer states vent can not be capped):

International Mechanical Code Section 501.3.1
2. For other product-conveying outlets: 10 feet (3048 mm) from property lines;


IRC 804.3.3
The termination of chimneys or vents equipped with power exhausters shall be located a minimum of 10 feet (3048 mm) from the lot line or from adjacent buildings. The exhaust shall be directed away from the building.

No and No.

To start with, the IMC is not applicable to residential installations.

Then, venting of combustion by-products is not a "product-conveying" exhaust, nor is venting of combustion by-products and "exhaust" nor is the vent system an "exhaust system" - which means that Chapter 5 Exhaust Systems is not applicable either.

First and foremost with codes it to select the correct code, second is to select the correct section and not mix up sections - start with what the Chapter is about, such as "Exhaust Systems" ... if it is not an "exhaust system" then that chapter is not applicable - no need to read any further.

Combustion-by products are vented through a venting system, so you need to start there ... in the correct code ... so the first thing is to start with the IRC, then go to venting, you will find this in the Mechanical Chapters:
(bold is mine)
- M1801.1 Venting required. - - Fuel-burning appliances shall be vented to the outdoors in accordance with their listing and label and manufacturer’s installation instructions except appliances listed and labeled for unvented use. Venting systems shall consist of approved chimneys or vents, or venting assemblies that are integral parts of labeled appliances. Gas-fired appliances shall be vented in accordance with Chapter 24.

That means you go to Chapter 24, Fuel Gas.
After looking through the sections listed for venting you will be directed to (for that appliance):
(bold is mine)
- G2427.2.1 (503.2.3) Direct-vent appliances.
- - Listed direct-vent appliances shall be installed in accordance with the manufacturer’s instructions and Section G2427.8, Item 3.

You start with the manufacturer's installation instructions AND G2427 ... but only Item 3 applies.
- G2427.8 (503.8) Venting system termination location.
- - The location of venting system terminations shall comply with the following (see Appendix C):
- - 3. The vent terminal of a direct-vent appliance with an input of 10,000 Btu per hour (3 kW) or less shall be located at least 6 inches (152 mm) from any air opening into a building, and such an appliance with an input over 10,000 Btu per hour (3 kW) but not over 50,000 Btu per hour (14.7 kW) shall be installed with a 9-inch (230 mm) vent termination clearance, and an appliance with an input over 50,000 Btu/h (14.7 kW) shall have at least a 12-inch (305 mm) vent termination clearance. The bottom of the vent terminal and the air intake shall be located at least 12 inches (305 mm) above grade finished ground level.


That is of no help (unless the installation instructions instructions contain something which helps), which is why I did not post it earlier.

HOWEVER ... Chapter 1, the Administrative chapter, IS applicable to EVERYTHING which follows to the extent applicable, which is why I posted those sections.

Another aspect which typically helps a lot when no help is received from the building department is to bend the ear of one of the city commissioners, and, if that is of no help, an investigative TV reporter can get a LOT of attention QUICKLY when that plume of combustion by-products is shown belching over into the front entry of the house next door ... THAT can get the ball (or balls if you know what I mean) rolling toward action and resolution.