THE HOUSE FILES · Plumbing
Real inspection examples of missing pipes, crawlspace terminations, pan-only drains, and a leaking discharge stub—and what proper piping should accomplish.
Yes. A water heater temperature-and-pressure (TPR / T&P) relief valve needs properly installed discharge piping so hot water or steam can be directed toward a safer location if the valve opens. Missing or improperly terminated discharge piping is a common installation concern. It does not, by itself, prove the relief valve is defective.
PLAN FOR CORRECTION
Have a qualified plumber install or correct the TPR discharge piping so it meets the water-heater and valve manufacturer instructions and applicable local requirements. If you see active leaking or discharge from the valve or pipe, arrange prompt evaluation—the cause needs to be determined, not just the pipe routing.
Do not cap, plug, or valve off a TPR discharge opening. If hot water is actively discharging, keep clear of the stream and seek prompt professional help.
The TPR valve is designed to open if tank temperature or pressure rises too high. Discharge piping is what directs that release away from people and finishes so the event is visible and less likely to cause injury or hidden water damage.
Manufacturer installation instructions commonly require discharge piping that is connected to the valve outlet, keeps the full outlet diameter, uses material listed for hot-water distribution, stays free of valves/caps/plugs and other restrictions, drains by gravity without prohibited traps or uphill runs, and terminates where discharge can be observed in a safer manner. Exact termination locations (for example floor-level vs approved exterior points) depend on the product instructions and local requirements—do not assume every installation must terminate outdoors or into a drain.
These photographs document common real-world discharge-piping problems. They do not establish tank condition, thermostat settings, expansion-tank performance, or why a valve may have released water.
Across multiple real inspections, TPR discharge piping was found missing, ending in a crawlspace, emptying only into a drain pan, or wet at an improper termination. In each case the report recommended routing discharge to an appropriate, observable location. One example also noted active leaking at the termination and called for evaluating the relief valve if needed.
Yes. A temperature-and-pressure relief valve needs properly installed discharge piping so that if the valve opens, hot water or steam is directed toward a safer location instead of spraying at the valve.
Discharge piping is generally run to an approved, safe termination point so a release is directed away from people. Terminating loosely in a crawlspace, or draining only into the pan, are common installation concerns an inspector documents.
A pan-only termination is a condition we frequently find and flag. The discharge piping should be installed to direct a release safely, and a qualified plumber can correct an improper termination.
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Status Plan for Correction
Gray steel water pipe common in homes built before the 1960s. It corrodes from the inside, restricts water flow, and eventually needs replacement—shown in real Upstate SC inspection findings.
View case filePlumbing
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A gray (sometimes blue) plastic water-supply pipe used from the late 1970s into the mid-1990s, no longer used in new construction and known to fail—often without warning. We still find it regularly in Upstate crawlspaces.
View case fileElectrical
Status Immediate Safety Concern
Open electrical covers and exposed splices on a water heater create a shock and fire risk at an always-on appliance.
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The most common defects we document during home inspections — from water heaters and electrical issues to crawlspace damage.
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