A Capped TPR, a Back-Pitched Discharge, and an Illegible Data Plate
A 2010 townhouse. The 50-gallon gas water heater sits on the garage floor beside a stored mower and a gasoline can; the data plate is faded and the model number cannot be read. The TPR valve is fitted with a 3/4-inch copper discharge line that runs 12 feet horizontally with a slight upward pitch toward the exterior wall, passes through the rim joist, and terminates 6 inches above grade outside with a threaded end closed by a brass cap. There is no drain pan; a floor drain sits 4 feet away. The garage is slab-on-grade, and the heater is 8 feet from the vehicle door.
1. Evaluate the TPR discharge arrangement and list what you would report.
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Judge it against what the valve is for: relieve pressure or temperature safely, by gravity, without obstruction.
- Brass cap on the threaded end: this defeats the valve completely. If pressure rises, the cap holds it and the tank or a fitting becomes the relief point. The discharge pipe must not be threaded or fitted with anything that can be capped.
- Upward pitch over 12 feet: discharge must fall and drain fully. A back-pitched run traps water, corrodes the copper, and can scale or freeze shut, so the valve may not relieve when it is needed.
- Termination: 6 inches above grade is low; check that it does not discharge onto a walkway, against the foundation, or onto the heater's own base. A route to the floor drain or to a safe exterior point is preferable.
- Sizing: 3/4 inch matches the valve outlet, which is correct.
Report all four as one safety item and recommend a licensed plumber correct the discharge piping. Do not operate the TPR yourself - a valve that has sat for years often will not reseat.
2. The data plate is unreadable and the heater sits on the garage floor. How do you handle the ignition-source question?
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The rule the call turns on: a gas water heater in a garage needs its ignition source at least 18 inches above the floor unless the unit is listed as flammable-vapor-ignition-resistant (FVIR), in which case it may be installed at floor level. You cannot read the plate, so you cannot determine which case you are looking at.
Do not assume. A unit on the floor next to a gasoline can is a real vapor-ignition risk, and the risk is invisible in a photograph. The date of manufacture, which you also can't read, is part of the answer.
Report: unit on the floor in a garage, data plate illegible, compliance not verified, gasoline stored in the same space, and a recommendation that a licensed plumber verify the model's listing using the plate or the manufacturer. If the buyer needs a yes/no before closing, the plumber provides it, not you.
Why not just write "elevated ignition source not present"? Because that asserts a fact you did not establish. "Not verified" is accurate, and it is enough to get the unit looked at.
3. The buyer asks whether the missing drain pan matters since there is a floor drain nearby. Answer the question as you would in the report.
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Depends on what a leak would damage, and here it is a garage slab - so the pan is best practice, not the headline.
- A pan with a drain line is required where a leak would damage the structure or finishes, or where the heater sits in a location that can't drain. On a slab with a floor drain 4 feet away, a sudden tank failure runs to the drain and does little harm.
- What matters more in this garage is everything else: the capped TPR, the back-pitched discharge, the unverified ignition height, and the stored fuel.
Report: note that no pan is installed, that the slab and nearby floor drain limit water damage, and that a pan piped to the drain is recommended as good practice, especially because the heater is in a space used for storage.
Why phrase it that way: it tells the buyer what actually threatens the house, and it keeps you from listing a low-consequence item as though it were equal to a defeated safety valve. Ranking findings is part of the judgement the buyer is paying for.