Why is my Rheem tank water heater not working?

First: is it safe to troubleshoot?

If you smell gas, do not light anything, touch switches or use a phone inside. Rheem's manual says to leave and call the gas supplier from a neighbor's phone, or the fire department if you cannot reach the supplier^[1]. See gas smell near the water heater.

This page is a neutral, symptom-based guide. We are not affiliated with Rheem and we do not repair water heaters.

Read the status light (gas tanks)

Most current Rheem gas tanks have a status light on the gas control. The pilot has to be lit to read a code, and the code repeats every three seconds^[1]. Count a few cycles.

Status light	Rheem's meaning	Rheem's suggested step
Off	Control off, pilot not lit, or low thermopile power	Follow the lighting instructions; check the thermopile connection
Constantly lit	Pilot recently went out and the thermopile is cooling	Follow the lighting instructions
1 blink	Normal operation	Set the temperature knob
2 blinks	Low thermopile voltage, pilot lit	Check thermopile connection and wires, inspect the pilot
4 blinks	High water temperature limit tripped	Contact a qualified service technician
5 blinks	Water temperature sensor failure	Contact a qualified service technician
7 blinks	Combination gas control (thermostat) failure	Contact a qualified service technician
8 blinks	False pilot flame signal	Contact a qualified service technician
9 blinks	Chamber sensor failure	Contact a qualified service technician
10 blinks	Chamber temperature shutdown	Contact a qualified service technician

Every row comes from Rheem's Use and Care manual for its FVIR residential gas models^[1]. Older Rheem and Ruud controls can label codes differently, so check the chart on your own heater. The 2-blink checks involve the gas control, so we treat them as pro work too.

Symptoms, likely causes and who fixes them

Symptom	Likely cause	Who fixes it
No light, pilot out	Pilot went out, thermopile, or gas supply	Homeowner relights per the label once; pro if it will not hold
4 blinks, very hot water before it quit	High limit tripped	Licensed plumber (scald risk)
5 or 7 blinks	Sensor or gas control failure	Licensed plumber
Burner will not relight after fumes or a blocked air inlet	Combustion shutoff device tripped	Licensed plumber
Electric tank, no hot water	Breaker, element, thermostat or high-limit	Homeowner checks breaker; pro for the rest
Rotten egg smell in the hot water	Water chemistry reacting with the anode	Pro, or water treatment
Relief valve drips after heating	Thermal expansion in a closed system	Licensed plumber
Water at the base	Fittings, drain valve, relief valve or a failed tank	Pro diagnosis

The combustion shutoff. Rheem's manual says these heaters have a device that shuts the heater down if combustion conditions are unsafe, such as flammable vapors or a blocked combustion air inlet, and to contact a qualified service technician if it trips^[1]. The manual also says not to block the air inlet openings around the base^[1].

Rotten egg smell. Rheem's manual explains that water high in sulfate or minerals can react with the anode's protective process and produce a hydrogen sulfide odor. It says chlorinating the water supply should minimize it^[1]. See rotten egg smell in hot water.

Dripping relief valve. The manual says periodic discharge may be thermal expansion in a closed system, and never to plug the relief valve outlet^[1]. See relief valve leaking or dripping.

What a homeowner can safely check

• Count the status light code and write it down.
• Confirm the gas supply valve is open and other gas appliances work.
• Follow the lighting instructions on the heater once or twice, no more.
• Keep the base clear of lint, boxes and stored chemicals.
• On electric tanks, check the double breaker once. If it trips again, stop.

Rheem's manual tells owners not to attempt repair of gas piping, the gas control, burners, venting or other safety devices, and to refer those to qualified service personnel^[1].

Maintenance that prevents repairs

Rheem's lifespan article recommends flushing the tank annually, replacing the anode rod every 3 to 4 years, and keeping water pressure around 40 to 60 psi^[2]. The Use and Care manual adds an annual anode inspection, with replacement when more than 6 inches of core wire is exposed^[1]. Anode work means draining pressure from the tank, so many owners hand it to a pro.

Warranty basics from Rheem

• Terms vary by model. The 6-year Rheem certificate we read gives 1 year of full warranty, including labor, then 5 years of limited parts and tank coverage. After the first year, labor, removal and reinstallation are the owner's cost^[4].
• When it starts. On that certificate, coverage runs from the documented purchase date. Without proof, it runs from the date of manufacture plus 30 days^[4]. Other Rheem certificates use different start rules, so read the one for your model.
• Registration. Rheem's warranty page says registering gives access to warranty benefits and can extend coverage. Checking warranty terms requires the serial number^[3].
• Serial number. Rheem's guide reads the first four digits as month, then year, of manufacture^[6]. Our age decoder does the math.
• Getting service. Rheem's manual says to contact your installer or service company first^[1]. Rheem's warranty page points owners to a local Rheem Pro, with the serial number ready^[3].

Costs and the repair or replace question

HomeGuide's national ranges, published August 2025^[5]:

Repair	Typical range
Thermocouple replacement	$100 to $325
Gas control valve replacement	$150 to $550
Igniter repair	$75 to $350
Heating element or thermostat (electric)	$100 to $350 each
Typical tank repair overall	$150 to $700

Service call fees of $50 to $200 may apply^[5]. These are not quotes.

Rheem's rule of thumb: tanks typically last 8 to 12 years. Repair often makes sense on units under 6 to 8 years old, and a repair costing more than 50% of a new unit usually means replacement^[2]. See repair or replace.

When to call a pro

• The status light shows 2 or more blinks, or the pilot will not stay lit after one or two tries.
• The combustion shutoff has tripped, or you see scorch marks near the burner door.
• The relief valve is releasing water steadily, or the water was scalding before the heater quit.
• Water is leaking from the tank, or an electric tank trips its breaker again.