Worried? Here's how to tell if expansion tank is bad
If you're noticing water dripping from your water heater's reduction valve or unusual pressure spikes in your plumbing, you're likely wondering how to tell if expansion tank is bad before a minor annoyance turns in to a flooded basement. These little tanks—usually sitting right over your water heater—don't seem like much, but they do a substantial job. They're basically the "shock absorbers" for your home's plumbing system. Whenever they fail, that will extra pressure has nowhere to move, and that's when things start busting.
Most people don't even think about their own expansion tank till there's a puddle on the ground. But catching the failing tank early can help you save a few hundred dollars and a whole lot of stress. Let's walk through how these items work, why they fail, plus the simple checks you can perform right this moment to observe if yours provides kicked the bucket.
What exactly does this tank do?
Prior to we dive directly into the tests, it will help to know what's going on within that metal cylinder. Your water heater works within a "closed loop. " When water gets sizzling, it expands—it's the basic rule of physics called heat expansion. Since your pipes are firm and water doesn't compress, that extra volume needs a place to go.
Inside the expansion tank, there's a heavy-duty rubber diaphragm. One side of that will diaphragm is loaded with pressurized air flow, and the additional side is open up to your drinking water system. When the particular water expands, this pushes against that will rubber balloon, compressing the air and maintaining your pipe stress stable. If that will rubber diaphragm tears or the air side loses its cost, you've got a "bad" tank.
The classic "Tap Test"
The easiest way to get a fast concept of what's occurring inside is the tap test. You don't need any tools for this—just your knuckles or a screwdriver handle.
Move over to your own expansion tank and provide it a several firm knocks. Begin at the top and work your path to the bottom. Since the tank is separated into two areas (air and water), it should appear different depending on where you strike it.
- The Surroundings Side: This would sound hollow and metallic, like an empty soda pop can.
- The Water Side: This will sound dull plus "thuddy, " since it's full of liquid.
If you tap the particular tank all more than and it sounds heavy and strong everywhere, that's a massive red flag. It usually means the diaphragm has failed as well as the entire tank has filled with water. A "waterlogged" tank is useless due to the fact water doesn't shrink, meaning your plumbing related is now using the full brunts of that thermal expansion.
Checking the air valve (the Schrader valve)
If the touch test was not yet proven, or if you simply want to end up being 100% sure, the next step involves the surroundings valve. On the end of the particular tank (usually the top or the part opposite the water pipe), there's a little plastic cap. Unscrew it, and you'll discover a valve that looks exactly such as the one on your car or bike tire. This is called a Schrader valve.
Here is the particular big test: Take a small tool or even even your fingernail and very quickly depress the small pin in the center of the particular valve.
- If atmosphere happens: That's a great sign! It means the tank still provides some pressure. Nevertheless, it doesn't suggest it's perfect (it might just be low on air), but a minimum of the diaphragm isn't completely shredded.
- If water happens: The particular tank is dead. There is simply no reason water need to ever be around the air side of the diaphragm. If drinking water squirts out of that valve, the particular internal rubber membrane has a hole in it, plus you need to replace the tank immediately.
- If nothing arrives out: The tank has lost its air flow charge. It may be a gradual leak with the device, or the diaphragm might be screwing up. You can test pumping this back plan the bike pump, yet if it happens again, the tank is toast.
Look for the "Relief Valve" warning signs
Sometimes the particular clearest way how to tell if expansion tank is bad isn't by looking with the tank by itself, but by looking with your water heating unit. Every water heating unit has a T& P (Temperature and Pressure) relief device. It usually includes a little silver handle and a pipe that runs straight down the side of the heater towards the floor.
This valve is a safety feature. If the pressure within the tank gets way too high, the valve opens to allow water out therefore the heater doesn't explode. If you see a small puddle under that will discharge pipe, or if you observe it dripping regularly, your expansion tank is likely the particular culprit.
When the expansion tank fails, the pressure spikes every single time the water heater kicks on. The particular T& P valve does its job by bleeding away from that extra pressure, but those valves aren't meant to open daily. If it's dripping, don't just replace the valve—check the expansion tank first.
Visual cues: Rust and corrosion
This might sound obvious, yet a lot associated with people overlook the physical condition from the tank. Because these tanks are often tucked away within dark corners or even behind the water heater, they can develop slow leaks that go undetected for months.
Take a flashlight and look at the particular connection where the tank screws into your plumbing related. Do you notice any "crusty" whitened or green buildup? That's an indication of the slow drip. Also, look in the "seam" of the tank—the middle part where the two halves are became a member of. If you see rust spots or bubbling paint right now there, the metal is corroding from the inside out. Actually if it is nevertheless holding air, the rusty tank is a ticking time bomb. You don't want to wait for it to actually burst.
Using a pressure gauge for the final verdict
If you would like to be medical about it, you can buy a cheap drinking water pressure gauge that will screws onto a standard hose bib (like your washing sink or maybe the drain valve at the end of your water heater).
- Screw the gauge onto a faucet and turn water on.
- Note the particular "static" pressure (when no water is running). It should usually be in between 40 and sixty PSI.
- Right now, watch the gauge while your water heater is managing a heating cycle.
If you observe the pressure measure climb significantly—say, through 50 PSI up to 80 or 90 PSI—it indicates your expansion tank isn't doing its job. A healthful expansion tank should keep that stress relatively stable also when water is heating up. If the particular needle is bouncing all over the place, that's the clear indicator of a bad tank.
Is it worthy of trying to fix a bad expansion tank?
In short: No.
If the diaphragm is torn (water taken from the air flow valve), there is no way to repair it. The tank is the sealed unit. If the tank is just low upon air, you may try to repressurize it, but a person have to perform it correctly. A person have to shut down the main drinking water, drain the stress from the pipes, plus then use a push to match the tank's air pressure to your home's water pressure.
However, within my experience, if a tank starts losing air, it's usually the starting of the finish. Most expansion reservoirs only last about 5 to 10 years. If your own is because age group range and performing up, it's much cheaper to spend the particular $50–$100 on a new one right now than to pay out for a restoration crew to dry out your cellar later.
Final thoughts
Knowing how to tell if expansion tank is bad isn't just for plumbers. It's a simple homeowner skill that can save a person a huge headache. If you are doing the faucet ensure that you it seems solid, or if you poke the particular air valve and get a face filled with water, you've obtained your answer.
Don't ignore the signs. If your own water heater is acting weird or you see those "warning drips" through the relief valve, take five moments to check the expansion tank. It's one of these small parts that will does a large job, and maintaining it who is fit is the best way to keep your plumbing system happy plus dry.