US Craftmaster: No Heat, Flashes, or a Leak
The Short Answer: A US Craftmaster that is cold, blinking, or wet is an AO Smith / State-family tank with a different jacket. Count the LED, paper-towel the leak, ohm the elements with the breaker locked off. A wet jacket is a replacement. A red flash code is a part — not a brand story and not Flex Seal.
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Search Intent & The Real Problem
Showers died, a light is winking through the access door, or the pan is wet. Craftmaster is builder-grade hardware from the American / AO Smith / State line — same electronic thermostat (ET), same 4500 W elements, same drain-valve junk. Forums will sell you a company history. You need a flash count, a dry part, or a new tank. Gas Craftmasters use a millivolt or electronic control; do not treat that LED like the electric one.
A green heartbeat with hot water is often normal — flashing green light. Five red flashes is a circuit, not a mystery — 5 flashes. Water at the base is leaking from the bottom.
What other guides get wrong
They open with who owned the factory in Johnson City. That does not heat a shower. They paste a Rheem flash chart onto a Craftmaster ET — Rheem 5-flash is the upper element; Craftmaster 5-flash is the lower. They condemn the tank because the plastic drain weeps. And they tell you to reset a dry-fire code without filling the tank.
Step-by-Step Troubleshooting
Step 1: Name fuel, model, and the actual complaint
| What you have | Path |
|---|---|
| Electric, LED through the upper door, no hot water | ET flash chart below |
| Electric, green blink, water is hot | Normal — 2 blinks/sec upper, 4/sec lower |
| Electric, pan wet, jacket dry | Drain, T&P, nipple, element gasket |
| Jacket wet, rust at the seam | Tank — replacement |
| Gas, standing pilot or LED on the valve | Not the electric chart — stay lit |
- What to look for: Rating plate (E / ES electric, G gas). Photo of the LED sticker inside the door. That sticker wins.
- Required tools: Flashlight, phone camera.
Step 2: Read the Craftmaster electric LED — do not guess
Green flash while heating is the ET saying an element is powered. Red is a counted fault, half-second on, half-second off, then a 5-second pause.
| LED | Meaning | First move |
|---|---|---|
| Green ~2/sec | Upper element on | Wait — it should recover |
| Green ~4/sec | Lower element on | Normal if water is heating |
| Dark | No 240 V, or dead LED | Breaker, then meter at the ET |
| 1 red | Dry-fire — power on with the tank not full | Fill, then reset. Do not fire empty |
| 2 red | High-limit / ECO | Cool down, reset once, find why it overheated |
| 3 red | Upper thermistor (part of the ET) | Licensed ET swap |
| 4 red | Upper element circuit | Ohm the upper; lower may still heat |
| 5 red | Lower element circuit | Ohm the lower; upper may still heat |
| 6 red | ET processor | Power cycle once; then ET |
| 7 red | Lower thermistor | Sensor / ET |
| 8 red | Energy Smart module (ESM), if equipped | Wiring, then module |
| 9–12 red | ET error | Wiring, then ET |
- What to look for: Count two full cycles. Lukewarm with 5-flash is a classic dead lower — the upper still makes a short hot burst.
- Required tools: Eyes. Breaker lock before any cover.
Reset after a 2-flash only when the tank is full and the cause is gone. Holding the ECO in is how thermostats burn up.
Step 3: Electric no-heat — breaker, fill, ohms
- What to look for: Double-pole 30 A off and on the wrong breaker is the usual “dead Craftmaster.” Tank must be full — a 1-flash after a drain or a new install is dry-fire. Wires lifted, power verified dead: a healthy 4500 W / 240 V element reads ~12–13 Ω across the screws (factory band is often 5–25 Ω across wattages). Infinite = open. Any screw-to-tank continuity = grounded, often after the sheath cracked.
- Required tools: Non-contact tester, multimeter, element wrench. No meter = hire it.
Replace an open or grounded element and a discolored ET. Resetting a carbonized ECO into a dead element is a closet fire.
Step 4: Leak — paper-towel the source
- What to look for: Bead on the plastic drain threads = valve, not tank. T&P discharge pipe wet = pressure or temperature, not the shell — gauge the house (static over 80 psi) and the expansion tank. Element gasket wet, jacket dry = gasket. Foam wet with rust at the base = dead tank. Same map as bottom leak.
- Required tools: Paper towel, flashlight. Hose-bib gauge if the T&P is the wet pipe.
Do not epoxy the shell. A glass-lined tank with a hole is scrap.
Step 5: Gas Craftmaster — different LED, same fuel rules
- What to look for: Pilot that will not hold, main that will not stay, or a gas-control LED. That chart is on the valve, not in the electric door. Low millivolts, FVIR lint, or an electronic-fault lockout are not “air in the line.” Do not purge fittings.
- Required tools: Photo of the valve sticker. Manometer work is licensed: about 3.5–7 in. w.c. natural gas / 10–11 in. w.c. LP at the appliance — confirm the rating plate.
When DIY Ends: Calling a Licensed Pro
Stop if the jacket is wet, the bushing spins, you smell gas, the T&P is streaming, the ET is charcoal, or a 1-flash already followed a dry tank. You may lock the breaker, count flashes, fill the tank, and ohm elements. You may not jumper an ECO, cap a T&P, or thread on a “universal” gas valve. A licensed electrician or plumber swaps the ET and elements on a sound tank. A licensed plumber replaces a leaking shell — same-day beats a collapsed subfloor.
Frequently Asked Questions
Q: Why is my US Craftmaster water heater not heating? A: No 240 V, a tripped ECO, an open element (~12–13 Ω is healthy at 4500 W / 240 V), or a red LED lockout. Count the flashes against the door sticker. A wet jacket is a new tank, not a new element.
Q: What does a flashing light on a Craftmaster mean? A: Green while it recovers is often normal. Red is a counted fault: 1 dry-fire, 2 high-limit, 4 upper element, 5 lower element. The sticker in that door wins over a Rheem chart.
Q: Can I repair a leaking Craftmaster myself? A: A plastic drain valve or an element gasket on a dry jacket, yes if you can isolate and prove power dead. A hole in the tank, no. Sealant on the shell is a delay until the floor fails.