Gas Water Heater Explosion?

[silli586]

Hi All,

I'm not sure why, but lately I have been overcome with this intense fear that our water heater is going to explode..like on that Mythbusters episode where they prove it can happen. Here is a little bit about our water heater:

For one thing, we rent, so it isn't technically ours (so I understand I personally can't make any repairs on it), but it is a 40 Gallon Richmond Natural Gas Water Heater. I don't think my landlord has ever had it professionally cleaned or inspected. When I look at the flame(which seems to be half orange half blue by the way), as it's reheating the water, I can see a TON of soot buildup on the burner. We also have soot on top of the water heater that I don't know if it's ever been cleaned off. I am aware of the carbon monoxide dangers of improper combustion and we do have a couple detectors installed.

Here is the kicker - I know I can (and should) test the TPR valve to make sure it's working properly - but he has the red tube the water would come out of installed into the ground! It literally goes from the valve into the floor where it's sealed in there; so even if I test the valve, how would I know if it's working? I have no way to see the water coming out and I have no idea where this hose goes too. I checked behind the house and can't see anything that would indicate it flows out there.

Finally, I'm pretty sure our state is a closed water system and we do not have a pressure relief tank, or pressure expansion tank whichever it's called. Which only makes me worry more!

So here is my question: Yes I know I need to talk to him about the concerns we see, however....just to ease my worries....is it a bad idea to turn the water heater to "off" every day and turn it back "on" only before taking a shower to get hot water? I really onlt want the hot water for a shower....I can do cold for everything else. Would that even protect against an explosion? Or is it a bad idea to have the pilot light turn on and off every single day and could result in a gas buildup or anything else? I'm just looking for something to relieve this fear! Any advice welcome!

 

[Terry]

The pilot light is always on.
You can turn down the heater to vacation mode when away, and then back up again. Most water heaters have a triangle for the 120 degree setting, and then it can rotate progressively hotter.
The T&P is set to relieve pressure at either 150 PSI or 210 degrees. The relief drain should daylight six inches above ground somewhere. What you would expect to see would be a 3/4" 90 out of the siding and then a pipe pointing down, and stopping six inches above ground. Sometimes those get plumbed into the crawlspace and forgotten.

 

[Sponsor]

 

[Sylvan]

UPC 608.5 Relief valves located inside a building shall be provided with a drain, not smaller than the relief valve outlet, of galvanized steel, hard drawn copper piping and fittings, CPVC, or listed relief valve drain tube with fittings which will not reduce the internal bore of the pipe or tubing (straight lengths as opposed to coils) and shall extend from the valve to the outside of the building with the end of the pipe not more than two (2) feet (610 mm) nor less than six (6) inches (152 mm) above the ground or the flood level of the area receiving the discharge and pointing downward. Such drains may terminate at other approved locations. No part of such drain pipe shall be trapped or subject to freezing. The terminal end of the drain pipe shall not be threaded. Or ASME A112.4.1.

 

[Jadnashua]

Other than verifying that the T&P valve is not physically stuck, it's not that easy to test to verify that it will actually work at the specified pressure and/or temperature. But, while most people do not manually open theirs to verify that the piston is not frozen, it isn't a bad idea and the instructions on most of them say to do it annually. But, be alerted that it doesn't always reseal properly if there's crud on the shaft. IF that's the case, it should be replaced, but at least you'd know if it could release if required.

 

[Cacher_Chick]

It would be common for the end of the T&P discharge pipe to be a couple of inches above the floor, but not going into the floor. Most renters would never as much as look at the water heater, unless their hot water stopped working.

The right thing to do is to bring your concerns to the landlord and give him an opportunity to take action. If your concerns are not addressed, then you call the municpal office/building inspector and tell them of your concerns and see where that gets you. Without having seen the installation, it would not be of much value to form an opinion based on an inexperienced eye.

 

[Cacher_Chick]

UPC 608.5 Relief valves located inside a building shall be provided with a drain, not smaller than the relief valve outlet, of galvanized steel, hard drawn copper piping and fittings, CPVC, or listed relief valve drain tube with fittings which will not reduce the internal bore of the pipe or tubing (straight lengths as opposed to coils) and shall extend from the valve to the outside of the building with the end of the pipe not more than two (2) feet (610 mm) nor less than six (6) inches (152 mm) above the ground or the flood level of the area receiving the discharge and pointing downward. Such drains may terminate at other approved locations. No part of such drain pipe shall be trapped or subject to freezing. The terminal end of the drain pipe shall not be threaded. Or ASME A112.4.1.

True, but WI has its own code which does not allow the T&P discharge to terminate outside of the room. In addition, it is permitted to allow the T&P discharge to be directed to the floor, as long as there is a floor drain for it to run to.

 

[silli586]

True, but WI has its own code which does not allow the T&P discharge to terminate outside of the room. In addition, it is permitted to allow the T&P discharge to be directed to the floor, as long as there is a floor drain for it to run to.

So is it possible there is a drain under the floor it's directed to? And I just can't see it? That's seems unsafe to me...this thing is literally like molded into the floor so I can't even move it.

 

[silli586]

Other than verifying that the T&P valve is not physically stuck, it's not that easy to test to verify that it will actually work at the specified pressure and/or temperature. But, while most people do not manually open theirs to verify that the piston is not frozen, it isn't a bad idea and the instructions on most of them say to do it annually. But, be alerted that it doesn't always reseal properly if there's crud on the shaft. IF that's the case, it should be replaced, but at least you'd know if it could release if required.

Are there other warning signs before an explosion would occur? I understand it can happen really fast but would temperature of water coming out of faucets be hotter than what thermostat is set at? Would i notice the burner running continuously? Obviously I'd have to watch it... Any precautions I can take to make myself feel better are helpful!

 

[Kebo147]

Do you have a carbon monoxide detector in place and in date? CO detectors are junk after a max of 7 years. All units are dated. If not...GET ONE! Based on what you have said, the relief valve needs to be addressed. I see a far bigger issue in the sooting you spoke about than the relief valve potential.

Yes you would expect to see much hotter temps from the faucet than what the unit is set for if the water heater might "explode". The relief is set for 210 degrees F. At my altitude, steam would come out of the faucets rather than hot water. The second criteria is 150 psi. What is your house pressure? Do you have a pressure reducing valve in place? What is the pressure of the the system providing water to the house? Is it city water?

You could crack a faucet and let it drip, much like people do to help prevent freezing and eliminate all fears of explosion. The biggest concern is the one you can't smell...CO. Are there issues with headaches, fatigue, cold like symptoms, moisture on the inside of windows...? Those are CO signs.

 

[Cacher_Chick]

Without a proper inspection by a qualified person, I would hesitate to say what you have or believe you have found. Water heater explosions are extremely uncommon, and it you are really concerned, you always have the option of making those phone calls to request assistance.

 

[silli586]

Do you have a carbon monoxide detector in place and in date? CO detectors are junk after a max of 7 years. All units are dated. If not...GET ONE! Based on what you have said, the relief valve needs to be addressed. I see a far bigger issue in the sooting you spoke about than the relief valve potential.

Yes you would expect to see much hotter temps from the faucet than what the unit is set for if the water heater might "explode". The relief is set for 210 degrees F. At my altitude, steam would come out of the faucets rather than hot water. The second criteria is 150 psi. What is your house pressure? Do you have a pressure reducing valve in place? What is the pressure of the the system providing water to the house? Is it city water?

You could crack a faucet and let it drip, much like people do to help prevent freezing and eliminate all fears of explosion. The biggest concern is the one you can't smell...CO. Are there issues with headaches, fatigue, cold like symptoms, moisture on the inside of windows...? Those are CO signs.

Hi there and thanks for your response. I take it you are saying the concern over sooting is the risk of carbon monoxide, correct?

I am a very paranoid person when it comes to carbon monoxide and actually have 3 detectors for our one level duplex. 2 are almost brand new. I also plan on buying one of those "low level" detectors that tells you even miniscule amounts.

Going back to the sooting....I should clarify I don't know how long the soot on top of the water heater itself has been there. We have lived here about 1 1/2 years and I never looked really until now. The soot on the burner I see when looking through the window could be a 5-8 year accumulation for all I know. If you take into consideration that amount of time is the soot less significant? I understand it's still not good but it's not like I'm cleaning it constantly and them it's reappearing within a week.

Not sure on the pressure questions.

Thanks!!!

 

[Kebo147]

Hi there and thanks for your response. I take it you are saying the concern over sooting is the risk of carbon monoxide, correct?

I am a very paranoid person when it comes to carbon monoxide and actually have 3 detectors for our one level duplex. 2 are almost brand new. I also plan on buying one of those "low level" detectors that tells you even miniscule amounts.

Going back to the sooting....I should clarify I don't know how long the soot on top of the water heater itself has been there. We have lived here about 1 1/2 years and I never looked really until now. The soot on the burner I see when looking through the window could be a 5-8 year accumulation for all I know. If you take into consideration that amount of time is the soot less significant? I understand it's still not good but it's not like I'm cleaning it constantly and them it's reappearing within a week.

Not sure on the pressure questions.

Thanks!!!

You have CO safety in place. I can sleep. A professional needs to look at this. You just touched an uninsulated combustion chamber and asked if it should burn you...YOU BET!!! You are out of your skill level and your continued attempts will hurt someone, mostly you. I mean no offense and don't want anyone hurt.

 

[silli586]

You have CO safety in place. I can sleep. A professional needs to look at this. You just touched an uninsulated combustion chamber and asked if it should burn you...YOU BET!!! You are out of your skill level and your continued attempts will hurt someone, mostly you. I mean no offense and don't want anyone hurt.

None taken. As a side note though, I in no way intended to perform maintenance like cleaning the burner by myself. Regarding the combustion chamber well, I wasn't actually in it...I was simply watching the flame pattern through the window, from the outside.. (when I noticed the soot buildup on burner) and my finger slipped. I did not remove the door leading into the chamber or anything like that. I know my skill level in this area is 0 and would not risk anyone's safety.

I will let my landlord know I noticed the soot on top of the heater and on the burner and see if he wants to do anything. Unfortunately he doesn't seem like the most proactive guy as I'd think maintenance on stuff like this would just be handled on a regular basis as it is....but...we will see.

 

[JRC3]

Take some high res pics and post them. You know what they say...A picture is worth a thousand words.

 

[Master Plumber Mark]

Dont worry so much..it will only make you sick....
you have about as much chance of a water heater exploding as hitting the power ball lottery...
I have only seen 2 of them blow up and I have both of them in my front window because
they are so extremely rare .... They do happen, but a lot more people have hit the lottery
than had a water heater blow up on them....and how many lottery winners do you know???


you have a much higher chance of it flooding you out because they leak all the time......
If the heater is less than 15 years old I would not worry about it....
ask the landlord to change the pressure relief valve if you are that paranoid....

just to get your shorts up in a bind look at these..... this one is just a small fire
really got this heater nice and toasty

and this one blew up

 

[Jadnashua]

For a WH to explode, your pressure would have to get excessive or the temperature would need to get so high that it could turn the water to steam - i.e., boiling. Because the WH is under pressure, just like in a car, that temperature that would allow it to boil and get to steam, is higher than the normal boiling point. Probably in the range of 240-250 degrees or so, but if it DID get that hot, and you opened a faucet, it would immediately flash into steam. The T&P valve, if it's working, should open if the pressure exceeds 150psi (normal home water pressure should be 80psi or less), and also will open if the water temp gets to 210-degrees. IOW, it would be strange to not notice one of the conditions that might start to be dangerous. Note, if you have a closed system (a check valve somewhere), you might have the T&P valve opening after a big hot water use as the WH restores the temperature and that water expands. If it's a closed system, there is nowhere for that larger volume of water to go, and it needs to leak somewhere, which usually is the T&P valve, but could be a leaking faucet or toilet fill valve, so you might not see it at the T&P (which would be hard if you can't see the drain!).