Wisconsin (WI) JOURNEYMAN PLUMBER
Restricted Appliance Exam Questions and
Answers | 2026 Update | 100% Correct.
1. A journeyman plumber in Wisconsin installing a natural gas-fired storage water
heater must ensure that the appliance is equipped with a temperature and pressure
relief valve rated at a maximum of _____ BTU/hr or as specified by the manufacturer.
A) 50,000
B) 75,000
C) 200,000
D) 400,000
Answer: D
*Explanation: For storage water heaters exceeding 1 gallon per 4,000 BTU/hr input, a
T&P relief valve is required. The Uniform Plumbing Code and Wisconsin amendments
set maximum rating at 400,000 BTU/hr for a single relief valve on a storage appliance.
Over this requires multiple valves or special engineering.*
2. When sizing a gas piping system for a restricted appliance in Wisconsin, the longest
length method requires that the pressure drop from the meter to the farthest appliance
does not exceed _____ inches of water column for natural gas at 7–10 inches WC supply.
A) 0.3
B) 0.5
C) 1.0
D) 2.0
Answer: B
*Explanation: Wisconsin Commercial Building Code and NFPA 54 allow 0.5-inch WC
pressure drop for low-pressure natural gas systems (under 14 inches WC). This ensures
adequate gas flow and appliance performance, especially for restricted appliances like
boilers or water heaters.*
,3. A restricted appliance includes which of the following types of equipment under
Wisconsin SPS 305 and SPS 384 regulations?
A) A gas-fired clothes dryer in a single-family home
B) A non-residential water heater with input exceeding 200,000 BTU/hr
C) A residential tankless water heater in an apartment building
D) A gas cooking range in a restaurant
Answer: B
*Explanation: In Wisconsin, "restricted appliance" typically refers to larger
commercial/industrial equipment that requires specialized licensing. Non-residential
water heaters >200,000 BTU/hr, commercial boilers, and large processing equipment are
restricted appliances. Residential dryers and ranges are not restricted.*
4. For a power-vented water heater installed in a mechanical room with limited
combustion air, the minimum net free area of combustion air openings from the
outdoors must be at least _____ square inches per 1,000 BTU/hr of total input for
appliances with restricted status.
A) 0.5
B) 1.0
C) 2.0
D) 3.0
Answer: C
*Explanation: Wisconsin code (adopting International Fuel Gas Code) requires 2 square
inches per 1,000 BTU/hr when using horizontal ducts to outdoors, or 1 square inch per
1,000 BTU/hr if vertical ducts. However, for restricted appliances in confined spaces,
more conservative 2 sq in/1,000 BTU/hr often applies.*
5. The minimum clearance from combustible materials for a single-wall metal vent
connector serving a restricted appliance with flue gas temperatures exceeding 400°F is
_____ inches.
A) 6
B) 9
,C) 12
D) 18
Answer: A
*Explanation: NFPA 54 and Wisconsin SPS 341 require 6 inches clearance for single-wall
metal vent connectors to combustibles. Type B vent requires 1 inch. Double-wall or
factory-built insulated vents have reduced clearances per listing.*
6. A restricted appliance located in an unconfined space (volume ≥ 50 cubic feet per
1,000 BTU/hr total input) is considered to have adequate combustion air if the space is
not tight. A "tight" construction means walls and ceilings have a maximum air infiltration
of _____ air changes per hour (ACH).
A) 0.1
B) 0.2
C) 0.4
D) 0.6
Answer: C
Explanation: Wisconsin definitions align with IFGC: a tight building envelope has less than
0.4 ACH when tested at 0.2 inches WC. For such spaces, engineered combustion air is
required regardless of volume.
7. When installing a gas-fired boiler classified as a restricted appliance, the condensate
drain from a condensing unit must be piped with material approved for acidic
condensate. The minimum required pH range for the drain material to resist corrosion is:
A) 2.0 to 3.5
B) 3.5 to 5.0
C) 5.0 to 9.0
D) 7.0 to 9.0
Answer: B
*Explanation: Condensate from condensing gas appliances typically has pH 3.5–5.0.
Wisconsin plumbing code requires corrosion-resistant materials such as PVC, CPVC, or
, polypropylene. Neutralizers may be required before discharging to sanitary sewer if pH
<3.5.*
8. The maximum allowable length of a flexible gas connector for a movable restricted
appliance (e.g., commercial food service equipment on casters) is _____ feet per
Wisconsin restrictions.
A) 3
B) 4
C) 6
D) 10
Answer: C
Explanation: NFPA 54 and Wisconsin code limit flexible connectors to 6 feet for movable
appliances, provided they are listed for the application. For stationary restricted
appliances, maximum length is 3 feet unless otherwise approved.
9. A restricted appliance vent connector must slope upward from the appliance to the
chimney or vent at a minimum rise of _____ inch per foot.
A) 1/8
B) 1/4
C) 1/2
D) 3/4
Answer: B
*Explanation: NFPA 54 and Wisconsin SPS 341 require 1/4 inch per foot upward slope
for vent connectors to ensure proper draft. No sagging or back-pitch is allowed.*
10. For a Category I (non-condensing, negative draft) restricted appliance, the vent
connector must have a minimum clearance of _____ inches from any combustibles when
using Type B vent material.
A) 0
B) 1
C) 3
D) 6
Restricted Appliance Exam Questions and
Answers | 2026 Update | 100% Correct.
1. A journeyman plumber in Wisconsin installing a natural gas-fired storage water
heater must ensure that the appliance is equipped with a temperature and pressure
relief valve rated at a maximum of _____ BTU/hr or as specified by the manufacturer.
A) 50,000
B) 75,000
C) 200,000
D) 400,000
Answer: D
*Explanation: For storage water heaters exceeding 1 gallon per 4,000 BTU/hr input, a
T&P relief valve is required. The Uniform Plumbing Code and Wisconsin amendments
set maximum rating at 400,000 BTU/hr for a single relief valve on a storage appliance.
Over this requires multiple valves or special engineering.*
2. When sizing a gas piping system for a restricted appliance in Wisconsin, the longest
length method requires that the pressure drop from the meter to the farthest appliance
does not exceed _____ inches of water column for natural gas at 7–10 inches WC supply.
A) 0.3
B) 0.5
C) 1.0
D) 2.0
Answer: B
*Explanation: Wisconsin Commercial Building Code and NFPA 54 allow 0.5-inch WC
pressure drop for low-pressure natural gas systems (under 14 inches WC). This ensures
adequate gas flow and appliance performance, especially for restricted appliances like
boilers or water heaters.*
,3. A restricted appliance includes which of the following types of equipment under
Wisconsin SPS 305 and SPS 384 regulations?
A) A gas-fired clothes dryer in a single-family home
B) A non-residential water heater with input exceeding 200,000 BTU/hr
C) A residential tankless water heater in an apartment building
D) A gas cooking range in a restaurant
Answer: B
*Explanation: In Wisconsin, "restricted appliance" typically refers to larger
commercial/industrial equipment that requires specialized licensing. Non-residential
water heaters >200,000 BTU/hr, commercial boilers, and large processing equipment are
restricted appliances. Residential dryers and ranges are not restricted.*
4. For a power-vented water heater installed in a mechanical room with limited
combustion air, the minimum net free area of combustion air openings from the
outdoors must be at least _____ square inches per 1,000 BTU/hr of total input for
appliances with restricted status.
A) 0.5
B) 1.0
C) 2.0
D) 3.0
Answer: C
*Explanation: Wisconsin code (adopting International Fuel Gas Code) requires 2 square
inches per 1,000 BTU/hr when using horizontal ducts to outdoors, or 1 square inch per
1,000 BTU/hr if vertical ducts. However, for restricted appliances in confined spaces,
more conservative 2 sq in/1,000 BTU/hr often applies.*
5. The minimum clearance from combustible materials for a single-wall metal vent
connector serving a restricted appliance with flue gas temperatures exceeding 400°F is
_____ inches.
A) 6
B) 9
,C) 12
D) 18
Answer: A
*Explanation: NFPA 54 and Wisconsin SPS 341 require 6 inches clearance for single-wall
metal vent connectors to combustibles. Type B vent requires 1 inch. Double-wall or
factory-built insulated vents have reduced clearances per listing.*
6. A restricted appliance located in an unconfined space (volume ≥ 50 cubic feet per
1,000 BTU/hr total input) is considered to have adequate combustion air if the space is
not tight. A "tight" construction means walls and ceilings have a maximum air infiltration
of _____ air changes per hour (ACH).
A) 0.1
B) 0.2
C) 0.4
D) 0.6
Answer: C
Explanation: Wisconsin definitions align with IFGC: a tight building envelope has less than
0.4 ACH when tested at 0.2 inches WC. For such spaces, engineered combustion air is
required regardless of volume.
7. When installing a gas-fired boiler classified as a restricted appliance, the condensate
drain from a condensing unit must be piped with material approved for acidic
condensate. The minimum required pH range for the drain material to resist corrosion is:
A) 2.0 to 3.5
B) 3.5 to 5.0
C) 5.0 to 9.0
D) 7.0 to 9.0
Answer: B
*Explanation: Condensate from condensing gas appliances typically has pH 3.5–5.0.
Wisconsin plumbing code requires corrosion-resistant materials such as PVC, CPVC, or
, polypropylene. Neutralizers may be required before discharging to sanitary sewer if pH
<3.5.*
8. The maximum allowable length of a flexible gas connector for a movable restricted
appliance (e.g., commercial food service equipment on casters) is _____ feet per
Wisconsin restrictions.
A) 3
B) 4
C) 6
D) 10
Answer: C
Explanation: NFPA 54 and Wisconsin code limit flexible connectors to 6 feet for movable
appliances, provided they are listed for the application. For stationary restricted
appliances, maximum length is 3 feet unless otherwise approved.
9. A restricted appliance vent connector must slope upward from the appliance to the
chimney or vent at a minimum rise of _____ inch per foot.
A) 1/8
B) 1/4
C) 1/2
D) 3/4
Answer: B
*Explanation: NFPA 54 and Wisconsin SPS 341 require 1/4 inch per foot upward slope
for vent connectors to ensure proper draft. No sagging or back-pitch is allowed.*
10. For a Category I (non-condensing, negative draft) restricted appliance, the vent
connector must have a minimum clearance of _____ inches from any combustibles when
using Type B vent material.
A) 0
B) 1
C) 3
D) 6
