What Home Inspectors Actually Check
A home inspector evaluates the gas distribution system from the meter to the appliances. This includes the gas meter location and condition, accessible supply lines and shutoffs, flexible connectors behind appliances, and visual signs of corrosion, improper materials, or mechanical damage.
Inspectors typically use a combustible gas detector to test for active leaks at accessible connections. This isn't a comprehensive pressure test of the whole system. It's a pass-over with a handheld detector near joints and valves.
What we can't assess: buried or concealed lines, lines inside finished walls, or the internal components of gas appliances. Those require specialized testing.
Common Gas Line Findings
Some findings come up constantly. Others are rare but significant.
Flexible Connector Issues
Older uncoated brass flexible connectors behind stoves and dryers are one of the most common gas findings. These corroded connectors have caused house fires and are no longer code-compliant in most jurisdictions. They're inexpensive to replace (under $50 for parts), but the finding is worth flagging to a plumber for confirmation and replacement. The Consumer Product Safety Commission has issued recalls on certain connector types going back decades.
Missing or Improper Shutoffs
Each gas appliance should have its own accessible shutoff valve within a few feet of the unit. Missing appliance shutoffs get flagged regularly, especially in older homes where the gas was roughed in before current code requirements. It's a straightforward fix but requires a licensed plumber in most states.
Improper Materials
Yellow CSST (corrugated stainless steel tubing) is a common modern gas line material. It's perfectly acceptable when properly bonded. The issue is that many CSST installations predate current bonding requirements. Without proper bonding, CSST can be damaged by lightning-induced electrical surges. If the report flags CSST without bonding, get an evaluation from a licensed plumber.
Older black iron pipe is generally fine if it's not corroded. Plastic gas lines (HDPE or polyethylene) are for underground use only and shouldn't appear above ground.
Corrosion and Mechanical Damage
Surface rust on black iron pipe is common and usually cosmetic. Active corrosion with pitting, scale buildup, or obvious deterioration is a different matter. The same goes for lines with kinks, crimps, or mechanical damage from renovation work. These get noted as requiring evaluation by a licensed plumber or the utility company.
When a Specialist Is Required
Some findings go beyond what an inspector can evaluate:
- Gas odor during inspection: If an inspector smells gas, the inspection stops. The utility company gets called. Period.
- Suspected buried line issues: If there are wet spots in the yard near buried lines, unexplained dead vegetation, or the utility has flagged prior leaks, a line pressure test by the utility or a plumber is the right step.
- Old cast iron lines: Some homes, especially pre-1940 construction, still have original cast iron gas lines. These can work fine or be severely corroded. A plumber with gas experience can evaluate service life.
- Post-renovation work: Unpermitted additions and renovations frequently disturb gas lines without proper inspection. Any area of the house that looks significantly modified warrants extra scrutiny.
The American Gas Association (AGA) notes that gas line inspections beyond the meter are typically the responsibility of a licensed plumber, not the utility. Your local utility may perform free safety checks on their portion of the line from the street to your meter.
How to Interpret Gas Line Findings in Your Report
Gas line findings generally fall into three buckets:
Monitor: Minor surface corrosion, accessible shutoffs that are stiff but functional, older flexible connectors that aren't the condemned brass type. These are worth noting but may not require immediate action.
Repair before closing: Active leak detected, condemned brass connectors, missing appliance shutoffs, improper materials. Repair costs are typically modest ($200-600 depending on what's needed), but you want documented work and permits.
Specialist evaluation required: CSST bonding concerns, suspected buried line issues, unexplained gas odor, extensive system modifications. You're looking at $150-400 for a plumber evaluation, with repair costs depending on findings.
Gas findings that seem minor often are. But they're worth resolving in writing before closing because gas work requires permits, and you want that paper trail.