You’d often have to flush your water heater to remove the sediments or do maintenance work on your heater. I’ve done this multiple times and I’ve broken down the process into a few simple steps.
The main Rheem water heater flushing instructions you should follow are:
- Turning off the gas or power supply to the heater.
- Attaching a garden hose to the drain valve.
- Shutting off the cold water supply.
- Draining the tank.
- Restoring power to the heater.
I’ll talk about how you can execute all these steps in detail in this guide. It’s an easy process and you can do it on your own. You’ll also learn a way to know the right flushing frequency for your water heater. So, let’s dive in!
Table of Contents
Why Should You Flush The Rheem Water Heater?
Before I dive deep into the flushing instructions, you should know why it’s important to flush the heater. The main reason behind it is to get rid of the sediment build-ups in the water heater.
The sediments will eventually damage the heating element in an electric water heater. They’ll also destroy the heat exchanger in tankless water heaters with time. Flushing the heater is the number one way to combat that.
If you don’t flush the heater from time to time, the sediments deposited on the water heater will wreak havoc. The tank can also be corroded with time, develop cracks and water would be leaking from it.
Besides, sediments pile up on the heating element and reduce its efficiency. So, you should remove them every now and then to get the most use out of the heater. You’d also have to drain the tank when you’re doing some maintenance work or replacing a component.
The drain valve can be clogged in some of the worst cases of sediment build-ups in the tank. It’ll be difficult to drain the water heater then. You can avoid all these issues by periodically flushing your water heater.
Rheem Water Heater Flushing Instructions [Gas & Electric]
You’d only need to flush the heater once or twice a year in most cases. But you’d have to do it more often if you live in an area with a hard water supply. In some rare cases, your heater may require monthly flushing depending on the level of hard water.
If you flush the heater correctly, you can prevent the major issues I’ve talked about earlier. All you’ll need for the job is a garden hose. Follow these steps to flush a tank-style Rheem water heater:
Step 01 – Turn Off The Gas Or Power Supply
Turn off the gas supply if you’re using a gas water heater. You can turn off the manual gas shutoff valve as well as the gas control thermostat. For electrical water heaters, shut off the power supply by flipping the circuit breaker.
Wait for the heater to cool down before proceeding to the next steps. Otherwise, there’s always the risk of scalding.
Step 02 – Attach A Garden Hose To The Drain Valve
Locate the drain valve at the bottom of the water heater. Take a garden hose and attach one end of it to the drain valve. Place the other end where you want to discard the water heater.
You can use a floor drain or run it outside your home if the garden hose is long enough. You shouldn’t use a bucket here as you’d be draining a lot of water and buckets don’t have such a high capacity.
Step 03 – Turn Off The Cold Water Supply
Close the shutoff valve at the cold water line so that no more water comes to the heater. Open a hot water faucet to relieve the pressure that has built up in the tank.
Step 04 – Drain The Tank
Open the drain valve by placing a flathead screwdriver and turning it. Allow the water to drain from the tank. If you don’t wait for the heater to cool down, the water will be too hot. So, make sure no one is around the garden hose when you’re draining the water.
When the water stops coming out, close the drain valve. Make sure you close the drain valve all the way. Otherwise, water could leak from it. Then, you can remove the garden hose attached to the drain valve.
Step 05 – Refill The Tank & Restore Power
Open the hot water faucet again. Then, open the cold water faucet. You should hear the heater starting to fill up at that stage. First, some air may come out of the faucet and the water would also come abruptly. Eventually, you should get a steady stream of water.
When that happens, turn off the hot water faucet. Wait for the tank to get completely filled with water. Only then, turn on the gas supply or the power supply back to the water heater.
If you turn on the water heater before completely filling the tank, the heating element can be shorted. So, don’t make that mistake.
Pro Tip: Drain a few quarts of water from the tank every month to remove the sediment deposits early on. It’s not necessary that you use the drain valve to do that. You can operate the T&P valve and get rid of the water through the water discharge pipe.
If you do that, you can place a bucket under the discharge tube to collect the water. Keep in mind that nobody should be around the heater at that time as the water will be hot.
How Often Do You Have To Flush The Heater
You already know how to flush the water heater. But you may be confused as to how often you have to do it. You have a general guideline but it’d be better to know exactly how often you should flush the heater.
There’s a cool trick you can use to know how often you should flush the heater. When you’re draining the tank, take a knee-high stocking and tie it to the end of the garden hose that drains the water. You can use a rubber end or a wire tie to do it. Here’s how it looks:
Now, the water will get drained through it but the sediments will get caught in the stocking. After you’re done flushing the heater, you can inspect the cloth. If you have about a tablespoon of sediments, you’re flushing at the right interval.
If there are way too many sediments more than that, you need to flush more often. After a few flushes, you’ll understand the right frequency of doing it for your water heater.
It all comes down to the hardness of the water, the thermostat settings, and the amount of hot water used. But once you find the right interval that keeps your heater happy, you can just maintain that. Hopefully, you’ll avoid many water heater issues by properly flushing the water heater.
Rheem Tankless Water Heater Flushing Instructions
The flushing process in tankless water heaters is different than that of tank-style water heaters. You don’t typically run any solution into the tank when flushing tank-style water heaters.
But when you flush the tankless water heaters, you’d have to run vinegar or some cleaning solution on the heater. You’ll need a pump to run this solution to the heater.
If you don’t have that, you can get a tankless water heater flushing kit from a nearby store. Those kits will not only have the pump but the solution as well that you’d need to flush the heater. They can also be used to descale the heat exchanger and clean it.
Once you have managed all the tools, you can move on to flushing the heater. Follow these steps to flush a Rheem tankless water heater:
Step 01 – Turn Off The Power and Water Supply
You have to turn off the power supply to the water heater. If your tankless water heater runs on gas, you need to cut off the gas supply as well. It’s not safe to flush the heater with the gas or power turned on.
So, make sure both of these things are turned off before you begin. Turn off the main water supply to the water heater as well. There should be a cold water isolation valve right under your tankless water heater. Turn the water supply off by turning it.
Step 02 – Flush The Heater
Connect a garden hose to all the drain valves. Attach the cold water hose to the output of a small circulation pump. You can also use a pond pump for this job too. Then, take a bucket and pour approximately 5 gallons of food-grade white vinegar into it.
Put the inlet hose of the pump and the drain hose of the hot water pump into the bucket. Then, open the drain valves and turn on the circulation pump. Let the solution run for at least 45 minutes. You can also let it run for an hour if you want to be on the safe side.
Step 03 – Restore The Original Condition Of The Heater
Once that time has passed, turn off the circulation pump. Drain the vinegar from the water heater and close the cold water drain valve. Turn on the main cold water supply and let fresh water run through the heater. Keep it that way for a few minutes so that the traces of vinegar can be removed.
After that time has passed, close the cold water main valve. Take off the cold water filter located at the cold water inlet. Clean it under cold running water to remove the dirt from it and reinstall the filter.
Turn on the water shutoff valves you have previously closed. Turn on a hot water faucet and make sure that the air is purged. Check for leaks. If there are any leaks, tighten the loose connections and fix them.
If there are no leaks, you can turn on the gas and water supply to the heater. Then, set the heater to your desired temperature. Turn on different hot water faucets and make sure that your unit is working properly.
FAQs:
How long does it take to drain a water heater?
For normal residential heaters that are less than 60 gallons, it doesn’t take too long. The draining process will take about 15 to 30 minutes. But larger tanks with a capacity of 80 gallons or more can take 40 to 60 minutes.
Where is the reset button on a Rheem water heater?
There is a reset button in the Rheem electric water heaters. It’s located on the upper thermostat in most cases. Once you remove the upper thermostat cover and the insulation, you should see the red reset button.
Can you make the draining process go faster?
Yes, you can open hot water faucets to drain the water quicker. You can also open the drain valve for a few seconds and close it to create a pressure difference. If you open the drain valve again, the water will go out faster.
How to drain a Rheem 50-gallon water heater?
The process of draining a 50-gallon Rheem water heater is the same as above. The only thing to keep in mind is that it’ll take longer to drain the water in large waters. That’s because the heater has more water in it.
How to drain the Rheem water heater with a plastic valve?
The process of draining is the same for both plastic and brass valves. You can turn the plastic valve directly with your hand. You won’t need a screwdriver for them as you would with the brass valves to start the draining process.
Conclusion
Now you know about the Rheem water heater flushing instructions in detail. It’s essential that you carry out this process at the right intervals so that too many sediments don’t pile up in the tank of your water heater.
Along with draining the tank, make sure you operate the T&P valve once or twice a year. If you follow the right maintenance, you’ll get to use your heater for many years to come. Check out my Rheem maintenance guide to learn more about it.