# Rheem Water Heater Valve

By Yan Kurniawan

Topic: Home & DIY

[Open the interactive Jig](https://ask.jig.com/j/L8DCaBrDEf73)

## Guide

### 1. Meet the drain valve

On a Rheem tank water heater, the valve people open most is the drain valve: the small brass tap near the floor\. Opening it lets water, and the grit that settles inside, flow out\. Drag anywhere around the heater to look at it from another side\.

Rheem suggests flushing a tank once a year, or every six months where the water is hard\.

### 2. Why open it?

Tap water carries dissolved minerals\. When the water is heated, some of them settle as sediment, a gritty layer on the floor of the tank\. That layer works like a blanket between the heat and the water, so the heater runs longer and uses more energy\.

The cutaway shows the steel jacket, a layer of foam insulation and the inner tank\.

### 3. Power off first

Before touching any valve, a grown\-up turns the heater off\. An electric heater is switched off at its breaker or switch; a gas heater has its control turned to Pilot or Off, as its manual shows\. An electric heater must never heat while its tank is empty\.

### 4. Close the cold\-water valve

Cold water enters through the pipe on top, marked here in blue\. Turn its yellow handle a quarter turn so it lies across the pipe\. Across the pipe means closed, in line with the pipe means open, so no new water can flow in\.

Some homes have a round wheel handle instead\. It closes clockwise and takes several full turns\.

### 5. Let air in

A full tank drains slowly unless air can get in, like a juice carton with no air hole\. Open a hot\-water tap somewhere in the house\. Rheem also has you lift the lever on the relief valve near the top of the tank\.

The relief valve is a safety valve\. It opens on its own if the water ever gets too hot or the pressure too high\.

### 6. Attach a garden hose

The drain valve ends in a garden\-hose thread\. Screw a hose on by hand and lead the other end to a floor drain or outdoors, somewhere that can safely take very hot water\.

On the tank side, the valve screws in with a 3/4\-inch pipe thread\.

### 7. Open the drain valve

Now the valve itself\. Drag the red lever, or press the button, and swing it a quarter turn until it points along the valve\. In line means open\. Open it slowly, and water and sediment flow out through the hose\.

Some Rheem drain valves have a round knob or a screwdriver slot instead\. They open counter\-clockwise\.

### 8. Flush, then close up

When the water runs clear, close the drain valve and take off the hose\. Lower the relief lever and open the cold\-water valve\. Once water flows steadily from the hot tap, close the tap and turn the power back on\.

A valve that will not turn, or keeps dripping, is a job for a plumber\. Never force it\.