Residential Mechanical Systems Inspection Checklist

1. 1. Is the job address posted in a visible location?

2. 2. Are the permits, approved plans, and mechanical construction documents on-site and accessible to the inspector?

3. 3. Is the permit information correct, including the address, permit number, and description of work?

4. 4. Have prior required mechanical rough-in inspections been approved?

5. 5. Is the required duct test report, as per the 2018 Washington State Energy Code (WSEC), on-site and completed by a qualified technician?

1. 1. Are gas appliances (water heaters, furnaces, and dryers) located in the garage equipped with a source of ignition that is a minimum of 18 inches above the floor unless listed as flammable vapor ignition resistant (FVIR) ?

2. 2. Are exposed ducts in the garage made of a minimum of 26-gauge sheet metal or other approved material with no openings into the garage?

3. 3. Are all ducts in the attic, garage, crawl space, or other unconditioned spaces insulated with a minimum of R-8 ?

4. 4. If equipment is subject to mechanical damage, has a bollard or wheel stop been installed ?

1. 1. Are drip legs installed at each appliance or where condensation could collect ?

2. 2. Is a sediment trap installed downstream of the appliance shutoff valve, as close to the inlet of the appliance as practical (Except for illuminating appliances, ranges, clothes dryers, and outdoor grills) ?

3. 3. Are unions or flex connectors installed between the shut-off valve and the appliance?

4. 4. Are unions or flex connectors not concealed within or extending through a wall, floor, partition, or appliance housing ?

5. 5. Is only one flex connector up to 6 feet long allowed on each appliance ?

6. 6. Is a shut-off valve required for each appliance, installed upstream of the union and accessible ?

7. 7. Is steel pipe support per the specified sizes provided ? • 1/2-inch pipe supported every 6 feet • 3/4 inch – 1-inch support every 8 feet • 1-1/4 inch or larger support every 10 feet • 1-1/4 inch or larger (vertical) support at every floor level. CSST per manufacturer

8. 8. Is piping not installed in or through a ducted supply, return, supply, exhaust, clothes chute, chimney or gas vent, ventilating duct, dumbwaiter, or elevator shaft? Is piping installed downstream of the point of delivery so it does not extend through any townhouse unit other than the unit served by such piping?

9. 9. Are vent piping for relief vents and breather vents vented directly and independently to the outdoors? Is vent piping for breather vents only connected to manifold arrangement where sized in accordance with an approved design (manufacturer installation instructions? Is the vent designed to prevent the entry of insects, water, and foreign objects)?

1. 1. Is the gravity venting system equivalent in area to the vent collar on the appliance, with allowances for performance standards ?

2. 2. Are single wall vents or B vents securely connected to the flue collars or draft hoods as recommended by the manufacturer ?

3. 3. Are vents connected to the common vent system within the same story requiring inlets to be at the highest level consistent with headroom and clearance to combustibles? Is it ensured that the vent system area cannot be less than the area of the largest vent plus 50% of the smaller flue collar added ?

4. 4. Are offsets in gravity vents installed with as many offsets as required so as not to exceed 45 degrees from vertical, except no more than one of 60 degrees is allowed, and horizontal runs don’t exceed 75% of the vertical height of the venting system?

5. 5. Are vent connectors serving Category 1 appliances not connected to any portion of a mechanical draft system operating under positive pressure?

6. 6. Are gas vents less than 12 inches in diameter in roofs with pitches less than or equal to 6/12 that can terminate a minimum of 12 inches above the roof as long as such vents are at least 8 feet from a vertical wall or similar obstruction?

7. 7. Are vent clearances to combustibles in compliance with the manufacturer's listings or performance standards ?

8. 8. Are single wall vents not penetrating walls, floors, or ceilings without proper thimble and piping arrangements limited to the space of the equipment to the roof or exterior wall ?

9. 9. Are vent terminations installed as per the manufacturer's listings ?

10. 10. Are mechanical draft venting systems installed in accordance with their listing, and do they terminate not less than 4 feet below or 4 feet horizontally from, and not less than 1 foot above a door, an operable window, or a gravity air inlet into a building, nor within 10 feet of a forced air intake nor within 12 inches above grade ?

11. 11. Where vents extending into an attic pass through insulated assemblies, is an insulation shield of 26 gage sleeve not less than 2 inches above the insulation secured in place and maintains required clearances to combustibles ?

12. 12. Are direct vent terminations following the manufacturer's installation instructions ?

13. 13. Are vent connectors' clearances to combustibles installed according to Table?

14. 14. Do single wall connectors not originate in an attic or concealed space or pass through an attic, inside a wall, or concealed space ?

15. 15. When a vent connector of a gas appliance with a draft hood is located within or passes through a cold area, is that portion of the connector a type B or type L vent?

16. 16. Are B vent chimneys supported above the roof per manufacturer's requirements ?

17. 17. Do Type B or L vents terminate at least 5 feet in vertical height above the highest connected equipment draft hood or flue collar?

1. 1. If a gas water heater has been installed is it checked to see if it is a mechanical inspection but may include plumbing if piping was moved?

2. 2. If an electric water heater is installed, is it checked to see if it is a plumbing inspection?

3. 3. Is the temperature and pressure relief valve required on water heaters ?

4. 4. Is the drain from the relief valve able to drain by gravity ?

5. 5. Is the drain pipe for the relief valve equal in size to the outlet valve ?

6. 6. Does the drain pipe terminate outside the building 6 to 24 inches above grade and has a soldered/glued (copper/plastic) on the elbow as needed to direct the flow toward the ground or terminate at an approved drain? It may not be directly connected to a sanitary sewer ?

7. 7. Is a gas water heater located in a garage raised to ensure the ignition source is at least 18 inches above the floor unless it's listed as flammable vapor ignition resistant ?

8. 8. Is seismic strapping installed as per Water Heater Tip Sheet 7 which follows: two straps, 1 in lower 1/3 and 1 in upper 1/3 and 3/4-inch wide? Are straps 22-gauge metal with each end of strap lag bolted onto two different studs? Is the lower point strapping at a 4-inch minimum distance above the controls ?

9. 9. When a water heater is in the normal path of a vehicle, is it properly protected ?

10. 10. Are water heaters in attics, attic-ceiling assembly, floor-ceiling assembly, or floor/subfloor assembly where damage may result from a leaking water heater, is a watertight pan of corrosion-resistant material installed with a 3/4-inch drain that is piped to an approved location?

11. 11. Is any water system provided with a check valve, backflow prevention, or a pressure regulating device that does not have a bypass feature at its source provided with an approved, listed, adequately sized expansion tank or other approved device having a similar function to control thermal expansion ? Exception: Instantaneous hot water systems installed per manufacturer.

12. 12. Do mechanical rooms with a floor drain or a standpipe subject to infrequent use require trap primers or other approved automatic means of maintaining their water seals? Is the trap primer valve accessible? Is it checked to see that it is working by verifying water is in the trap

13. 13. Is it ensured that fuel-fired water heaters are not installed in a room used as a storage closet? Is a water heater installed in a bedroom or bathroom in a sealed enclosure so that combustion air will not be taken from the living space? Are direct-vent water heaters not required to be installed within an enclosure?

1. 1. Is there a minimum working space of 30 inches wide and 30 inches deep on the control side of the furnace or air handler?

2. 2. Are clearances from combustible construction maintained as per the appliance listing ?

3. 3. Is the clearance from grade equipment supported on a concrete pad or approved material extending a minimum of 3 inches above the adjoining ground ?

4. 4. Is the condensate line set up for gravity drainage to an approved drain or condensate pump, with secondary disposal as needed ?

5. 5. For condensing appliances, is the venting carried out following the installer's instructions ?

6. 6. Are ducts sealed to prevent leaks (WSEC R403.3.2) and tested per RS-33 (WSEC R403.3.3) unless located entirely within the conditioned space of the building?

1. 1. Is each dwelling unit equipped with a whole-house mechanical ventilation system, and does it operate continuously or with intermittent off controls as required?

1. 1. Is the distance above the top of the cooktop to unprotected combustible material, not less than 30 inches and 24 inches if exceptions are met?

2. 2. Are clearance requirements for adjacent combustible surfaces in compliance with the manufacturer's installation instructions ?

1. 1. Is the fireplace factory-built, certified, listed, and labeled? Is it tested and certified according to WA. St. Bldg. Code standard 31-? Is the testing performed by WA ST. DOE, and the US. EPA accredited laboratory?

2. 2. For Certified Masonry and Concrete fireplaces, and heaters - are they tested and certified to WA. St. Bldg. Code standard 31-2? Is testing performed by WA ST. DOE, and the US. EPA accredited laboratory (R1004.1.2, WA State Amendment)?

3. 3. For Solid Fuel burning appliances and fireplaces – Are tight fitting metal/ceramic doors used, and certified to test No. 11-Negative pressure test, Section 12.3, of ULCS627-M1984 for outside combustion air–duct 4 inches min., and 20 feet max. length (R1006.6, WA State Amendment)?

4. 4. Are hearth extensions readily distinguishable from the surrounding floor and in accordance with the fireplace listing ?

5. 5. Are gas logs in solid fuel-burning fireplaces installed per the manufacturer's instructions ?

6. 6. Are appliance shutoff valves located in the same room, and within 6 feet of the appliance? Are appliance shutoff valves located in the fireplace firebox installed as per the appliance manufacturer’s instructions? Are shutoff valves for vented decorative appliances and room heaters permitted to be installed in a remote area from the appliance where such valves are provided with ready access, permanent identification, and serve no other appliance? Are shutoff valves installed at a manifold–within 5 feet of the appliance, but other requirements apply, as above?

7. 7. Are decorative shrouds used at chimney terminations listed and labeled for use with specific chimney systems?

8. 8. Are gas logs in solid fuel-burning fireplaces installed as per the manufacturer’s instructions?

9. 9. If gas logs have a pilot, do they have a listed safety shutoff valve?

1. 1. Is a 4-inch metal dryer exhaust duct installed with a smooth interior as per the manufacturer’s instructions?

2. 2. Is an approved flexible listed metal duct connector, up to 8 feet long, used to connect the dryer to the vent, ensuring it does not extend into the wall, floor, or ceiling?

3. 3. Has a minimum of 100 square inches of makeup air been provided for closets designed for the installation of clothes dryers that exhaust more than 200 CFM?

4. 4. For determining dryer duct length, is the exhaust duct limited to 35 feet for natural gas dryers, with deductions of 2.5 feet for each 45-degree elbow and 5 feet for each 90-degree bend?

5. 5. Alternatively, has the maximum length been determined based on the manufacturer’s installation instructions, with the make and model of the dryer provided to the code official at the rough-in?

1. 1. Is flex duct supported according to the manufacturer’s installation instructions, with a maximum spacing of every 4 feet, and without any kinks or tight bends?

2. 2. Are ducts in crawl spaces supported at least 4 inches above the ground or conforming to other applicable standards?

3. 3. Are ducts, boots, and connectors used for heating or cooling insulated to R-8?

4. 4. Have all exhaust ducts in unconditioned spaces, such as those from bathrooms or ranges, been insulated to at least R-8?

5. 5. When equipment is installed in a crawl or attic space, is there a light switch and outlet located at or near the appliance?

6. 6. Has a passageway of continuous solid flooring been installed, not less than 24 inches wide from attic access to a 30-inch wide work platform in front of the furnace?

7. 7. Is there an access opening that is large enough to remove the largest piece of equipment, but not less than 30 inches by 22 inches?

8. 8. Is the access opening located not more than 20 feet from the equipment?

1. 1. Are exterior gas lines adequately protected against weather conditions?

2. 2. For appliances installed in outdoor locations, have they been listed or adequately protected from outdoor environmental factors?

3. 3. Is the sizing of louvers and grills based on the net-free area of the grill, with wood louvers assumed to have a 25% free area and metal louvers and grills having a 75% free area? Are screens used with no mesh size smaller than 1/4-inch?

4. 4. If combustion air ducts are provided from outside of the building, have they been supplied according to the general rules for combustion air supply as below: 1) For vertical ducts: (2) openings, each having 1 square inch per 4000 Btu/h of total input of all appliances in the space. 2) For horizontal ducts: (2) openings each having 1 square inch per 2000 Btu/h of total input of all appliances in the space. 3) One opening in the upper 12 inches and one opening in the lower 12 inches of the room. 4) When the one-opening method is used, locate the opening within 12 inches from the top of the enclosure and provide 1 square inch per 3000 Btu/h or total input rating of all appliances in space. 5) The minimum cross-sectional area of each vent opening is 3 inches. Note: For specific applications, contact the local jurisdiction

5. 5. When the building is of ordinary construction (homes built prior to 1986) and the area of a confined space is less than 50 cubic feet per 1000 Btu/h of aggregate input rating of appliances, has combustion air been taken from an adjacent space, meeting the requirements outlined below? 1) The minimum cross-sectional area of each vent opening is 3 inches. 2) One opening in the upper 12 inches and one opening in the lower 12 inches of the room. 3) Where vertical ducts are used each opening requires 1 square inch per 4,000 Btu/h of total input rating of all appliances in the space. 4) Where horizontal ducts are used each opening requires 1 square inch per 2,000 Btu/h or total input rating of all appliances in the space. 5) When the one opening method is used, locate the opening 12 inches from the top of the enclosure and provide 1 square inch per 3000 Btu/h or total input rating of all appliances in the space.

6. 6. When the building is of ordinary construction and the area of a confined space is less than 50 cubic feet per 1000 Btu/h of aggregate input rating of appliances, is combustion air taken from an adjacent space when installed as follows: 1) A minimum of 100 square inches of combustion air is required. 2) One opening in the upper 12 inches and one opening in the lower 12 inches of the room.

7. 7. Are all appliances secured in place as per the manufacturer's listing?

8. 8. Have heat sources been provided in each habitable room, as required ?

1. 1. Do the approved plans specify the types of heating and cooling systems, including their efficiency requirements and any necessary energy credits?

2. 2. For ducts to be considered inside conditioned space, do they meet one of the following criteria: • Are all duct systems located completely within the continuous air barrier and within the building’s thermal envelope? • Are all heating, cooling, and ventilation system components installed inside the conditioned space, including forced air ducts, hydronic piping, hydronic loops, convectors, radiators, and is combustion equipment direct vent or sealed combustion? •For forced air ducts, is a maximum of 10 linear feet of return ducts and 5 linear feet of supply ducts permitted to be located outside the conditioned space, provided they are insulated to a minimum of R-8?

3. 3. For ducts located outside the building’s thermal envelope, are they insulated to a minimum of R-8? Are ducts within a concrete slab or in the ground insulated to R-10 with insulation designed for below-grade use?

4. 4. Is it ensured that HVAC supply and return register boots are properly sealed to the subfloor, wall covering, or ceiling that they penetrate?

5. 5. For all detached one- and two-family dwellings and multiple single-family dwellings (townhouses) up to three stories in height above the grade plane using electric zonal heating as the primary source, has an inverter-driven ductless mini-split heat pump been installed in the largest zone in the dwelling?

6. 6. For additional energy efficiency requirements (energy credits), have the minimum number of credits been achieved based on the dwelling unit size and other criteria, as follows: 1. Small Dwelling Unit: 3.0 credits For units less than 1500 square feet in conditioned floor area with less than 300 square feet of fenestration area or additions to existing buildings greater than 500 square feet of heated floor area but less than 1500 square feet 2. Medium Dwelling Unit: 6.0 credits For all dwelling units not included in Options 1, 3, or 4) 3. Large Dwelling Unit: 7.0 credits 4. Dwelling units serving R-2 occupancies: 4.5 credits 5. Additions less than or equal to 500 square feet: 1.5 credits

7. 7. Do the drawings included with the building permit application clearly identify the selected options and their corresponding point values, regardless of whether separate mechanical, plumbing, electrical, or other permits are utilized for the project?