What will happen if I forgot to turn off the water heater?

Question

I just left my home in Michigan for an extended winter vacation (6 months). I left the thermostat on 52 degrees, shut off the water supply in the basement, and drained the faucets. I have a gas water heater. It's 20+ years old (original). I turned it down to the lowest temperature setting ("warm"). Should I have turned OFF the water heater? I'm not even sure there's an on/off switch. Could something bad happen if I don't? Should I find a friend to go in and turn off the water heater? If so, how to do it? At the circuit breaker box in the basement? What about the water heater's pilot light? And what if the water heater can't be drained? Also, should I have unplugged the washer and dryer? I think I have a gas dryer. Help!

I just left my home in Michigan for an extended winter vacation (6 months). I left the thermostat on 52 degrees, shut off the water supply in the basement, and drained the faucets. I have a gas water heater. It's 20+ years old (original). I turned it down to the lowest temperature setting ("warm").

Should I have turned OFF the water heater? This website (http://www.stopleaks.com/waterh.htm) says to make sure to TURN OFF the gas supply to the water heater BEFORE turning off the water supply, but it doesn't tell you what will happen if you don't do it that way. Now I'm worried. I'm not even sure there's an on/off switch.

Could something bad happen if I don't? Should I find a friend to go in and turn off the water heater? If so, how to do it? At the circuit breaker box in the basement? What about the water heater's pilot light? And what if the water heater can't be drained? Also, should I have unplugged the washer and dryer? I think I have a gas dryer. Help!

Ok, I got some great responses, thanks!! Some of the answers provided conflicting info, though, so now I have more questions... Since I left the heater on anyway, maybe the easiest thing to do would be to just have someone go in and turn the water supply back on? Surely, the pipes will not freeze if the house is always heated to 50+ degrees. OR, alternately, if the gas supply to the water heater is turned off (and subsequently, the pilot light goes out - should it be blown out???), surely the water left in the heater tank will not evaporate or freeze?

Oh, and I'm not really on vacation... I'm in Cali doing an internship (I like to think I'm on vacation).

Answer 1

Have someone such as the gas utility provider or a qualified plumbing contractor go to your home to shut off the gas supply to the water heater - not to the entire house! If your house is heated by a gas-fired heating appliance such as a forced air furnace or a hydronic (water) heating system, shutting off the gas to the entire house will also shut off the gas to your heating system. Since you did not say that you fully winterized the potable water piping system and the plumbing drain and waste system, shutting off the heat to the entire house will guarantee that you'll return to extensive plumbing piping and fixture damage in the spring.

A water heater is a pressure vessel. If it should develop a slow leak while you're gone, the water level in the tank could drop below the temperature sensing probe on the temperature/pressure relief valve. This probe is normally immersed in the water inside of the tank. Since you said that you left the thermostatic control on the water heater set to "warm," it would then be possible for the burner to ignite and to heat the partially filled tank to the point that the water in the tank would boil and turn to steam. If the temperature/pressure relief valve failed to function because its temperature sensing probe was no longer immersed in the water in the tank and its pressure relief mechanism also failed, the steam pressure in the tank could cause the tank to explode. An exploding residential water heater is capable of destroying a house not to mention tearing its own gas supply line loose in the process allowing gas to flow into the home - or what remains of it.

Do the smart thing and have the gas to the water heated turned off.

In the future, have someone show you how to turn the gas to the unit off and how to relight the pilot light when you return.

Answer 2

Ideally you should have turned the water heater to "off" so that the heater does not continue heating the water in the heater. The fact that you shut off the water supply means that if all the water boils away in the water heater there is no way for the water to be replenished in the water heater .. which may be an issue. If you can have somebody help you I would get them to turn the water heater to off (at the temperature setting area). Leave the pilot light burning if turning the knob to off does not shut the pilot off too .. do NOT blow out the pilot..you could land up creating a buildup of gas in your house which could explode. Leave the circuit breaker box alone. Unplugging the washer and dryer is not a big deal BUT you should turn off the water to the washer and dishwasher (ok since you shut off the water). The gas dryer ideally should have the gas shutoff for the dryer turned to off.

All of this being said, quite frankly the EASIEST solution might be just to call your GAS company to just go SHUT OFF YOUR GAS outside at the meter ... that will take care of EVERYTHING .. water heater will not heat anything, pilot light out, gas line to dryer off .. problem solved!!

Answer 3

Whoa, stop. Everything's fine. It was a stroke of luck that you left it on. Your absence will run across the winter in Michigan. Leaving the water heater is one more protection step against broken pipes due to freezing. The water heater is built to self-regulate. Do not turn it all the way off. If the pilot blows out, the gas will be shut off at the thermo-couple. Everything will be fine.

You might want to have someone stop by on a monthly basis, just to check for vagrants, pilot lights, & problems, though. 6 months is a long time.

Answer 4

If you shut the water off you need to shut the gas off to the water heater and the pilot will go out and it will be off. Also drain the tank so it don't freeze.

I say this because when the water evaporates out of the tank you can start a fire.

I live in a cold climate and I work in maintenance field, I suggest you tell them to shut the gas off to the water heater and it will be fine. If water heater is 20 plus years old you need a new one. when you get home. Good Luck

Answer 5

There is a high possibility that they'll get ill. you should constantly watch the fish often. Most fish that get over 83 degrees F start to get major side effects such as brain damage, lower their immune system, bacterial infections, stress, lack of hunger, shock, and of course death. But you don't want to cool the tank down to quickly either, because reveling cold water at least 4 degrees lower than the temperature that the tank's originally at can cause "most" of these same effects. So I'm just saying to watch the fish (closely) and set your heater to a lower temp. or get a better heater such as an automatic shutting off heater. +This is RTCking saying good luck on fish keeping and I hoped this helped you+

Answer 6

Sounds like you did everything right. The water heater should be fine on warm. Gas water heaters do not rely on electricity. No problem there. If your washing machine is in a heated area, you're OK. If you've survived previous winters in this house, I'd say enjoy your vacation, you've got nothing to worry about.

Answer 7

The hot water tank is fine. At the lower temperature setting the water won't get hot. The washer is fine cause you shut off the water supply. Just relax, enjoy your vacation, and send me details on how you can afford a six months vacation. I have to get back to work after two weeks.

Answer 8

It will explode