423720 — Plumbing and Heating Equipment and Supplies (Hydronics) Merchant Wholesalers
Description
This industry comprises establishments primarily engaged in the merchant wholesale distribution of plumbing equipment, hydronic heating equipment, household-type water heaters, and/or supplies (as defined in the official U.S. Census Bureau 2022 NAICS Manual).
Exclusions & Cross-References
- Selling and installing plumbing, heating, and air-conditioning equipment--are classified in Industry 238220,
- Plumbing, Heating, and Air-Conditioning Contractors;
- Merchant wholesale distribution of warm air heating and air-conditioning equipment--are lclassified in
- Industry 423730, Warm Air Heating and Air-Conditioning Equipment and Supplies Merchant Wholesalers;
- and
- Merchant wholesale distribution of household-type gas and electric appliances (except water heaters and
- heating stoves (i.e., noncooking)), room air-conditioners, clothes dryers, and/or household-type audio or
- video equipment--are classified in Industry 423620, Household Appliances, Electric Housewares, and
- Consumer Electronics Merchant Wholesalers.
Overview Facts
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 5064 - Electrical Appliances, Television and Radio Sets (via SIC1987:5064→NAICS1997:42162→2002:423620→2007:423620→2012:423720→2017:423720→2022:423720)
- SIC 5074 - Plumbing and Heating Equipment and Supplies (via SIC1987:5074→NAICS1997:42172→2002:423720→2007:423720→2012:423720→2017:423720→2022:423720)
Suggested Product Service Codes (Advisory)
The following Product Service Codes (PSCs) are advisory suggestions aligned with this NAICS code. Note: NAICS and PSC codes map to different dimensions of procurement (industry vs. product/service). There is no official binding 1:1 crosswalk.
- PSC L045 — Technical Representation Services: Plumbing, Heating, and Waste Disposal Equipment
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Frequently Asked Questions (FAQ)
Is NAICS code 423720 valid in 2022? ▾
Yes, 423720 is a valid 6-digit 2022 NAICS national industry code representing 'Plumbing and Heating Equipment and Supplies (Hydronics) Merchant Wholesalers' under Sector 42 in the official classification index.
What is the SBA size standard for NAICS code 423720? ▾
The Small Business Administration (SBA) has established a small business size standard of 200 employees for NAICS code 423720 (Plumbing and Heating Equipment and Supplies (Hydronics) Merchant Wholesalers), calculated based on employees.
What is the legacy SIC equivalent for NAICS 423720? ▾
According to official Census Bureau concordance tables, NAICS code 423720 (Plumbing and Heating Equipment and Supplies (Hydronics) Merchant Wholesalers) maps to legacy 1987 Standard Industrial Classification (SIC) codes: 5064 - Electrical Appliances, Television and Radio Sets, 5074 - Plumbing and Heating Equipment and Supplies.
Related Pages & Tools
Further regulatory reference links for NAICS code 423720:
- Sector 42 Directory Hub — List of related industries in the Wholesale Trade sector.
- SIC ↔ NAICS Crosswalk Tool — Look up mappings between legacy SIC codes and modern classifications.
- NAICS 423720 to SIC Crosswalk — Bidirectional mapping to legacy SIC codes (Plumbing and Heating Equipment and Supplies (Hydronics) Merchant Wholesalers).
- SBA Size Standards Guide — Complete rules and averaging periods for small business classifications.
- Calculating Annual Receipts Guide — Detailed worked example of revenue calculation rules.
- IRS Principal Business Activity Guide — How NAICS codes map to corporate and entity tax filings.