If I had balls, they'd be shrunken...

December 4, 2012 6:26 AM

Why does my hot water heater's pilot light keep going out?

I just moved into a new house (yay!), but the hot water heater pilot light keeps going out. It's relatively easy to relight, but a fairly large nuisance to not have hot water when expected. The heater is gas, 50some gallons, wrapped in fiberglass insulation, in the unheated garage. It sits in a closet-like enclosure that's missing a door/4th wall. There's a large piece of wood that leans against the closet, acting as the door. The access panel area to the pilot light has a removable metal face that is always on (except when we take it off for relighting purposes). The closet is on the landing of the garage stairs (there's a small apartment over the garage), and directly next to a door that leads outside.
The first time it went out we'd been moving, so both the car-sized garage door and the human sized garage door had been left open all day, so I'm thinking a draft knocked it out.
This time, the heater went out overnight, when both doors were shut.
Ideas? I'm hesitant to attach the piece of wood to the front of the closet as it's large/bulky, and I'm small...if I'm the one who has to pry it off later, it would be relatively difficult.
Any help would be much appreciated!

posted by csox to home & garden (10 answers total)

When the pilot is lit, is the flame a healthy, steady blue flame, or is it yellow or flickery? I'm thinking there might be some cobwebs or other detritus gumming up the works.
posted by jon1270 at 6:30 AM on December 4, 2012

This happened to us when we had a new house in Nashville. Wind coming down the ventallation line kept blowing it out. Our inspector told us it was an issue, there was a thingy missing, and the builder came and fixed it (after we woke up to freezing water in the winter.)

Call the builder, they need to fix it.
posted by Ruthless Bunny at 6:31 AM on December 4, 2012

Last time that was happening to me, I was told that I needed to replace the thermocouple/generator. It's a relatively easy fix, two wires and a nut.

If the thermocouple isn't generating electricity, the water heater is set up to shut off the gas 'cause it thinks the pilot light has gone out.
posted by straw at 6:33 AM on December 4, 2012 [3 favorites]

Brand new house? Call your builder and get this fixed.

csox: "I'm hesitant to attach the piece of wood to the front of the closet as it's large/bulky, and I'm small...if I'm the one who has to pry it off later, it would be relatively difficult. "

You can buy self adhesive magnet material on a flexible roll like a really thick tape. 6" in each of the four corners on both panel and frame will secure the panel while still being easy for anyone to remove.
posted by Mitheral at 6:36 AM on December 4, 2012

The flame is steady and blue. Unfortunately, the house isn't new (just new to me).
Who does one call to look at these things? I'm not the home-owner, just a roommate, and the home-owner is brand new to homeownership. Turns out there's a pretty steep learning curve to these things. Thanks for the ideas so far! I'll be back in a few hours to update as needed
posted by csox at 6:46 AM on December 4, 2012

Unless you have a major malfunction, this is likely to be a very easy fix, and not uncommon. There is a piece called a thermocouple, and it has a very simple job. It sits in the flame of the pilot light, and as long as it stays hot, it keeps the pilot light going. When it cools down, it shuts off the pilot light. This is to prevent your house from blowing up if the pilot light goes out for some reason, since you wouldn't want the gas to keep going.

If the thermocouple isn't working correctly, your pilot light will go off intermittently. We had the exact same problem as you do.

The part is likely to be about $5 at your local home improvement store. You literally unscrew the old one, and screw in the new one, making sure it is all lined up correctly. For our water heater we also had to unscrew one of the small gas pipes. The only tools required were an adjustable wrench and a screwdriver. It took about 30 minutes to do it and verify that nothing was leaking. If anyone in your house is handy, it is definitely something that can be done yourself, as long as you take proper precautions when working around gas. You can find tutorials online on how to replace it and how to make sure the gas isn't leaking afterwards. It's all relatively easy.

That being said, if you are uncomfortable working around gas, feel free to hire a professional, they should be able to get it done in less than an hour.
posted by markblasco at 7:11 AM on December 4, 2012 [3 favorites]

Here's a basic description of the process
posted by markblasco at 7:13 AM on December 4, 2012

As mentioned above, it is likely to be either the thermocouple, a persistent draft, or dirt and/or debris in the jet.

If I were you I would start with the easiest first, clean the jet. Get a can of compressed air and use it to blow out the jet and the area around it. See if that fixes it.

If not, replace the thermocouple, if that doesn't do it, work at finding a way to prevent drafts (be safe there is fire involved here)..

Lastly, call an appliance repair place and have them come and solve the problem.
posted by HuronBob at 7:25 AM on December 4, 2012 [2 favorites]

Who does one call to look at these things?

One calls a plumber.
posted by Ruthless Bunny at 9:44 AM on December 4, 2012 [1 favorite]

Get a can of compressed air and use it to blow out the jet and the area around it.

Make sure the pilot light is out first! Many types of off-the-shelf compressed air/gas dusters are flammable.

Your friendly local plumber should be able to tackle anything you're not comfortable with.
posted by xedrik at 2:29 PM on December 4, 2012