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70th Anniversary of Purl's Sheet Metal & Air Conditioning

Serving The Fresno & Madera Area


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Weird Water Heater Noises and What They Mean

water-heater-tankYou need your water heater working steadily now more than ever. And that means it’s more important than ever to stay on top of potential water heater problems and their signs. The faster you schedule Fresno, CA water heater service when you think something is wrong, the faster and easier the repair job will be for our professionals. You don’t want to call for repairs after the water heater has failed—you want to get ahead of the problem.

As with heating and air conditioning systems, odd noises are one of the ways a water heater gives off warnings that something is wrong with it. Below we’ve listed the more common caution sounds you may hear from your water heater. Call us for assistance when you notice these noises. We’ll find out what’s wrong and have it fixed.


Kettling is a kind of popping noise people often hear from water heaters. Kettling usually occurs because of excess sediment gathered along the bottom of the tank. This sediment layer traps water between it and the heat exchanger, causing the water sandwiched between them to boil and rise through the sediment. This creates the popping noise. The layer at the bottom may be sediment or hard water deposits. Whatever it is, you’ll need professionals to flush the tank and possibly clean it.


Yes, this is an alarming sound. But no, your water heater is probably not on the edge of exploding. The rumbling sounds usually means either hot and cold water mixing at the top of the tank (often due to a broken dip tube) or the water is overheating. A broken dip tube will need to be replaced. If the water is overheating, it may be due to limescale inside the tank, although there are other possibilities. Call our technicians to investigate and find out what’s wrong.


Another unpleasant sound, this is often because of restrictions on water flow from problems with the inlet control valve. If the valve is partially closed, it will cause a screeching noise as water tries to flow through it.


You can probably guess what this means, since it’s a similar sound to water overflowing from a pot and landing on the hot burners of a range. This is the sound of water leaking from the tank or connection points and dripping onto the gas burners. Leaks of any type are a huge problem for a water heater and must be fixed right away. This requires professional technicians.


This sound is called water hammer, the result of the sudden stopping of water when a valve shuts off. The shockwaves from the abrupt change of direction is what creates the “hammer” sound. This may not be coming from the water heater itself, but elsewhere in the plumbing. If it is coming from the water heater, something has removed the pressure cushion in the expansion tank, or there is a collapsed flue tube. It’s serious, whatever the cause, so call our technicians to investigate it.

Purl’s Sheet Metal & Air Conditioning: “Quality Is the Cornerstone of Our Success” since 1952. Call us when you need water heater help.

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