What’s That Bubbling Noise From My Water Heater? - Sun Heating & Cooling, Inc.

What’s That Bubbling Noise From My Water Heater?


As we’re getting into the Halloween spirit here at Sun, we want to talk about a spooky, scary bubbling noise you might hear in your home, caused by your water heater! We’ll walk you through the exact steps of how to drain your water heater to get rid of the “bubble, bubble, toil and trouble”!

Yes, if you hear a bubbling noise, it isn’t a witch’s brew in a cauldron!

Instead, it’s probably the part of your HVAC system that’s most similar to a cauldron: your water heater!

Basically, the tank collects calcium and lime. You can’t do anything about it! But what happens is, water gets trapped underneath the calcium and lime layer. Then, because the bottom of the tank is where your burner is, when the water starts heating up and bubbling, it’s fighting to get above the calcium and lime sediments. This causes bubbling and boiling noises (sounds like a coffee maker) or perhaps more of a rumbling noise.

Whatever it sounds like to you, it’s not only very loud, annoying (and, yes, a bit spooky), but also potentially dangerous!

 The tank could actually burst, causing thousands of dollars in damage!

How do you avoid such a scary mishap?

Well, you could flush your water heater tank yourself. Here’s how, step by step:

Step 1: 

Find the thermostat by the bottom of the tank, and turn it off — that’s the case if you have a gas powered water heater. If you have an electric one, just turn off the breaker switch to your water heater. Voila!

Step 2 (only with gas water heater):

If you’re gas-powered, there’s an extra step: turn off the gas valve.

Step 3: 

Turn off the cold water valve. This is usually located near the top of the water heater, but you’ll also be able to recognize it because it’s commonly colored blue (cold).

Step 4:

Run at least one faucet in your home, so you don’t have empty water lines creating pressure while you’re draining the water out of the tank.

Step 5:

Attach a hose to the spigot on the hot water heater, before turning the spigot, and letting the water drain out to the end of the hose (which is preferably outdoors)! 

Step 6: 

Go back to the cold water valve and turn it back on again, so you can get a nice look at what the tank water looks like. Go take a look at this water coming out the end of the hose. Does it look clear? Probably, yes! But that doesn’t mean there wasn’t a sediment build-up. You probably can’t see the calcium and lime in the water…but that doesn’t mean it wasn’t there! So let this water continue draining out, and congratulations, now you’ve fixed your water heater bubbling noise problem!

Step 7:

Your last steps are mainly just undoing what you’ve done: turn the spigot off, and unscrew the hose. Then, go and turn off the faucet (the one you had turned on to prevent pressure in the water line). Turn on the hot water at that same sink. This is just to get any excess air out of the line. You should only be feeling cold water, coming out of that sink, considering that your hot water heater was turned off! Turn the water off at that sink. Then, go back out to your hot water heater and turn the gas valve back on!

That was a lot of “steps within a step,” but now your water heater is back the way you initially left it. All that’s left to do now is to turn it on.

Step 8:

Officially turn your brand spanking new water heater back on. You’ll do this either by turning the thermostat to “on” for a gas water heater, or turning the breaker box switch for an electric water heater.

Step 9:

Wait for the new water coming into your tank to have a chance to heat up. Then, turn on your hot water and make sure it works. 

Hopefully that the bubbling noise is gone! This is something you should do about once a year, so why not during Halloween time? 

If you keep up this routine maintenance, you’ll never hear the “bubbling brew” ever again.

If you don’t feel comfortable going through all these steps by yourself, let Sun guard your water heater against spooky problems. We provide plumbing services, including water heater maintenance and repair.

Schedule an appointment online or give us a call at (248) 986-1506!

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