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Troubleshooting Common Gas Water Heater Issues, pt 1

 Posted Friday, April 1, 2016.

Some common gas water heater problems can be solved in just a few minutes, by any capable adult. With a few instructions, the right parts, and a few minutes, you can get your hot water back in action. We’re fast when it comes to service calls-- but we’ll never beat you to the water heater in your own home!

First, a precaution. Before you do any work on a gas water heater (or any gas appliance, for that matter), ensure there is no gas leak present. Listen for a hissing sound that indicates a gas leak. Also be aware of the smell of natural gas. Natural gas has a distinct smell thanks to a required odorant. If you smell a strange odor (some describe it as smelling of garlic, rotten eggs, or sulfur) near your water heater, gas furnace, or any gas line, leave the area and call your gas provider immediately.


Natural gas is flammable, and if it has been allowed to accumulate, it can combust explosively if even a small spark or flame is present.


My Gas Water Heater Isn’t Making Hot Water

This is commonly caused by a pilot going out. If this happens, it’s likely nothing to be alarmed about. If the pilot has been out for a long time, and gas has been escaping into a room with no ventilation, check for any gas buildup. The gas flow should have been cut off when the pilot went out because of a sensor called the thermocouple. If you can vent the area, do so.

Fortunately, pilots are made to be conveniently re-lit. Near the bottom of your water heater there will be a panel with a removable cover. There are likely instructions for lighting the pilot on or near that panel. Newer water heaters have an electronic ignition, but if you have an older model you may need a flame source of your own to get the fire to take. Follow the instructions on your water heater and you should have hot water back in no time!

My Pilot Won’t Stay Lit

There are a few causes for a pilot refusing to stay lit. The most common and easily remedied cause is a bad thermocouple. The thermocouple is the sensor that detects whether the pilot is lit, and is supposed to cut the gas supply if the pilot is out. If the thermocouple thinks the pilot is out when it’s not, it will kill the gas supply and thus your supply of hot water.

Now, replacing a faulty thermocouple is fairly more involved than re-lighting the pilot. It will require several steps, including researching what kind of thermocouple belongs to your water heater, removing the old thermocouple (which requires removing the burner assembly), installing the new parts and re-assembling the burner assembly.

Unfortunately a thorough how-to guide for every common water heater out there is too much for a single article to handle. Fortunately, there are some universal steps.

Your local supply store likely has generic thermocouples that will fit most models of water heater. You’ll want to take your current thermocouple in when finding a replacement, to match the lengths and thread direction (some are left-handed threads). If the generic thermocouple won’t fit, you can likely find a match for your water heater by looking online.

Next week we’ll go over removing the burner assembly in order to get to the thermocouple. If you’re feeling comfortable with what we’ve gone over so far, you should have no problem with the process.

If you’re not feeling so confident, just call Nazzaro & Sons Plumbing & Heating Inc. and we’ll have a professional over to your place to take care of it for you. Call us at 978-256-3586, or contact us online and we’ll get in touch with you!

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