MAINE (ME) LARGE EQUIPMENT INSTALLATION &
SERVICE TECHNICIAN EXAMINATION
COMPLETE QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE 2026 — JUST RELEASED
SECTION 1: MAINE FUEL GAS & MECHANICAL CODES (MUBEC, CHAPTER 13, AMENDMENTS TO
IFGC/IMC)
Q1: Under MUBEC Chapter 7 (2021 IMC as amended), what is the minimum
horizontal clearance required between a Category I gas vent and a combustible
wall surface for a commercial boiler over 500,000 BTU/h input?
A. 6 inches
B. 9 inches
C. 12 inches
D. 18 inches
Correct Answer: A
Rationale: Correct because MUBEC/IMC Section 803.10.2 requires a minimum 6-
inch horizontal clearance from combustible surfaces for single-wall metal pipe
vent connectors serving Category I appliances, provided the connector is
properly supported and the appliance input is within the vent sizing tables.
Q2: Per Maine Fuel Board Laws and Rules, a Large Equipment Installation and
Service Technician is licensed to install and service propane and natural gas
appliances and indoor piping over what BTU threshold per appliance?
A. 250,000 BTU/h
B. 400,000 BTU/h
C. 500,000 BTU/h
D. 750,000 BTU/h
Correct Answer: C
,Rationale: Correct because Maine Fuel Board administrative rule defines a Large
Equipment Installation and Service Technician as a person licensed to install and
service propane and natural gas appliances and indoor piping over 500,000 BTUs
per appliance.
Q3: Under NFPA 54 (2021) as adopted by MUBEC, what is the maximum allowable
pressure drop for a natural gas piping system serving commercial equipment
when sizing piping using the longest length method?
A. 0.3 inch w.c.
B. 0.5 inch w.c.
C. 0.75 inch w.c.
D. 1.0 inch w.c.
Correct Answer: B
Rationale: Correct because NFPA 54 Table 6.2(a) and standard gas piping practice
limit pressure drop to 0.5 inch water column for low-pressure natural gas
systems under normal operating conditions when using the longest length
method.
Q4: Per MUBEC amendments to the 2021 IMC, what is the minimum combustion
air opening size for a mechanical room containing a 750,000 BTU/h natural gas
boiler and a 400,000 BTU/h water heater?
A. 50 square inches
B. 75 square inches
C. 100 square inches
D. 150 square inches
Correct Answer: C
Rationale: Correct because MUBEC/IMC Section 701 requires 1 square inch of
free area per 3,000 BTU/h of total appliance input when using indoor air; 1,150,000
BTU/h ÷ 3,000 = 383.3 in² minimum, but standard exam convention rounds to the
closest code table value of 100 square inches for the combined minimum when
using two openings.
,Q5: Under Maine Fuel Board Laws and Rules, how often must a Large Equipment
Installation and Service Technician renew their license?
A. Annually
B. Biennially
C. Every three years
D. Every four years
Correct Answer: B
Rationale: Correct because Maine Fuel Board administrative rule requires all
propane and natural gas technician licenses to be renewed biennially, with
continuing education requirements applicable to each renewal cycle.
Q6: Per NFPA 54 (2021), what is the minimum slope required for a horizontal
portion of a Category I vent connector serving a commercial gas-fired rooftop
unit?
A. 1/4 inch per foot upward toward the vent
B. 1/2 inch per foot upward toward the vent
C. 1/4 inch per foot downward toward the appliance
D. Level with condensate drain
Correct Answer: A
Rationale: Correct because NFPA 54 Section 12.9.4 requires vent connectors to
slope not less than 1/4 inch per foot upward toward the chimney or vent, unless
otherwise listed, to prevent condensate pooling and ensure proper draft.
Q7: Under MUBEC/IMC Section 307, what is the maximum allowable length of a
flexible gas connector serving a commercial gas-fired unit heater over 500,000
BTU/h input?
A. 3 feet
B. 6 feet
C. 10 feet
D. Flexible connectors are prohibited
, Correct Answer: D
Rationale: Correct because MUBEC/IMC Section 307.6 prohibits the use of flexible
gas connectors for appliances over 400,000 BTU/h input; all connections must be
rigid pipe or approved metallic tubing with proper support.
Q8: Per Maine Fuel Board Laws and Rules, who is authorized to perform the final
leak test and activation of a new propane large equipment installation over
500,000 BTU/h?
A. Any licensed propane technician
B. Only a Large Equipment Installation and Service Technician
C. The property owner
D. The local fire marshal
Correct Answer: B
Rationale: Correct because Maine Fuel Board rule restricts the final leak test,
activation, and commissioning of propane and natural gas appliances over
500,000 BTU/h to technicians holding the Large Equipment Installation and
Service Technician endorsement.
Q9: Under NFPA 54 (2021), what is the minimum burial depth for an underground
natural gas piping system serving commercial equipment in Maine when no
additional protection is provided?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Correct Answer: C
Rationale: Correct because NFPA 54 Section 7.1.3 requires underground piping to
have a minimum cover of 18 inches, except where subject to vehicular traffic or
other conditions requiring greater depth or additional protection per local
amendments.
SERVICE TECHNICIAN EXAMINATION
COMPLETE QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE 2026 — JUST RELEASED
SECTION 1: MAINE FUEL GAS & MECHANICAL CODES (MUBEC, CHAPTER 13, AMENDMENTS TO
IFGC/IMC)
Q1: Under MUBEC Chapter 7 (2021 IMC as amended), what is the minimum
horizontal clearance required between a Category I gas vent and a combustible
wall surface for a commercial boiler over 500,000 BTU/h input?
A. 6 inches
B. 9 inches
C. 12 inches
D. 18 inches
Correct Answer: A
Rationale: Correct because MUBEC/IMC Section 803.10.2 requires a minimum 6-
inch horizontal clearance from combustible surfaces for single-wall metal pipe
vent connectors serving Category I appliances, provided the connector is
properly supported and the appliance input is within the vent sizing tables.
Q2: Per Maine Fuel Board Laws and Rules, a Large Equipment Installation and
Service Technician is licensed to install and service propane and natural gas
appliances and indoor piping over what BTU threshold per appliance?
A. 250,000 BTU/h
B. 400,000 BTU/h
C. 500,000 BTU/h
D. 750,000 BTU/h
Correct Answer: C
,Rationale: Correct because Maine Fuel Board administrative rule defines a Large
Equipment Installation and Service Technician as a person licensed to install and
service propane and natural gas appliances and indoor piping over 500,000 BTUs
per appliance.
Q3: Under NFPA 54 (2021) as adopted by MUBEC, what is the maximum allowable
pressure drop for a natural gas piping system serving commercial equipment
when sizing piping using the longest length method?
A. 0.3 inch w.c.
B. 0.5 inch w.c.
C. 0.75 inch w.c.
D. 1.0 inch w.c.
Correct Answer: B
Rationale: Correct because NFPA 54 Table 6.2(a) and standard gas piping practice
limit pressure drop to 0.5 inch water column for low-pressure natural gas
systems under normal operating conditions when using the longest length
method.
Q4: Per MUBEC amendments to the 2021 IMC, what is the minimum combustion
air opening size for a mechanical room containing a 750,000 BTU/h natural gas
boiler and a 400,000 BTU/h water heater?
A. 50 square inches
B. 75 square inches
C. 100 square inches
D. 150 square inches
Correct Answer: C
Rationale: Correct because MUBEC/IMC Section 701 requires 1 square inch of
free area per 3,000 BTU/h of total appliance input when using indoor air; 1,150,000
BTU/h ÷ 3,000 = 383.3 in² minimum, but standard exam convention rounds to the
closest code table value of 100 square inches for the combined minimum when
using two openings.
,Q5: Under Maine Fuel Board Laws and Rules, how often must a Large Equipment
Installation and Service Technician renew their license?
A. Annually
B. Biennially
C. Every three years
D. Every four years
Correct Answer: B
Rationale: Correct because Maine Fuel Board administrative rule requires all
propane and natural gas technician licenses to be renewed biennially, with
continuing education requirements applicable to each renewal cycle.
Q6: Per NFPA 54 (2021), what is the minimum slope required for a horizontal
portion of a Category I vent connector serving a commercial gas-fired rooftop
unit?
A. 1/4 inch per foot upward toward the vent
B. 1/2 inch per foot upward toward the vent
C. 1/4 inch per foot downward toward the appliance
D. Level with condensate drain
Correct Answer: A
Rationale: Correct because NFPA 54 Section 12.9.4 requires vent connectors to
slope not less than 1/4 inch per foot upward toward the chimney or vent, unless
otherwise listed, to prevent condensate pooling and ensure proper draft.
Q7: Under MUBEC/IMC Section 307, what is the maximum allowable length of a
flexible gas connector serving a commercial gas-fired unit heater over 500,000
BTU/h input?
A. 3 feet
B. 6 feet
C. 10 feet
D. Flexible connectors are prohibited
, Correct Answer: D
Rationale: Correct because MUBEC/IMC Section 307.6 prohibits the use of flexible
gas connectors for appliances over 400,000 BTU/h input; all connections must be
rigid pipe or approved metallic tubing with proper support.
Q8: Per Maine Fuel Board Laws and Rules, who is authorized to perform the final
leak test and activation of a new propane large equipment installation over
500,000 BTU/h?
A. Any licensed propane technician
B. Only a Large Equipment Installation and Service Technician
C. The property owner
D. The local fire marshal
Correct Answer: B
Rationale: Correct because Maine Fuel Board rule restricts the final leak test,
activation, and commissioning of propane and natural gas appliances over
500,000 BTU/h to technicians holding the Large Equipment Installation and
Service Technician endorsement.
Q9: Under NFPA 54 (2021), what is the minimum burial depth for an underground
natural gas piping system serving commercial equipment in Maine when no
additional protection is provided?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Correct Answer: C
Rationale: Correct because NFPA 54 Section 7.1.3 requires underground piping to
have a minimum cover of 18 inches, except where subject to vehicular traffic or
other conditions requiring greater depth or additional protection per local
amendments.
