Gas Water Heater won't turn on !?!

[footprintsinconc]

Hello everyone!

our gas water heater turned of by itself and it wont turn back on. i even turned everything off for a day and then tried to ignited the pilot.

the unit is only 2.5 yrs old. it came new with our new house. the unit at pilot are in enclosed complete with only a viewing window. when i push down on the button, the pilot does ignite, but after a few minutes of holding the button, when i let go of it, the pilot goes out! i dont know what to do anymore.

what do you think is happening? what should i do?

thanks in advance for the help!

[ragswl4]

Hello everyone!

our gas water heater turned of by itself and it wont turn back on. i even turned everything off for a day and then tried to ignited the pilot.

the unit is only 2.5 yrs old. it came new with our new house. the unit at pilot are in enclosed complete with only a viewing window. when i push down on the button, the pilot does ignite, but after a few minutes of holding the button, when i let go of it, the pilot goes out! i dont know what to do anymore.

what do you think is happening? what should i do?

thanks in advance for the help!

The flame from the pilot light heats a sensor that then tells the main gas valve that the pilot light is on and lets the gas go to the pilot light without you holding down on the button. It then also allows the main gas valve to send gas to the burner as needed by the setting on the thermostat. (Safety device) I have had this problem before but always with older water heaters but I suppose yours could be the same problem. I replaced the item myself, I think it's called a thermistor. Available at your local Borg or Lowes or ACE. With the newer water heaters I am not sure if this same design is used.

[Ed62]

It sounds like you might need a new thermocouple. Is that the same as a thermistor?

Ed

[DonHo]

I agree with Ed, sounds like a theromcouple to me.

DonHo

[JoeyGee]

I had the EXACT problem a few weeks ago and it was the thermocouple. Mine is the old style where I could open it up and replace it myself. Long story short--after I discovered another issue after I replaced the thermocouple I had to call a pro.

The pro informed me that on some of the lower end newer units if a part like a thermocouple (or any part of the ignition system goes out) you need to replace the whole tank, due to the sealed combustion chamber that is now required. I don't know if that's true or not, but it's what he said. There are some sealed units that you can open and replace parts on, though.

[Tom Slick]

It sounds like a thermocouple to me too.

a thermocouple isn't the same as a thermistor. a thermocouple generates electricity when heat is applied to it. a thermistor changes resistance when heat is applied. I paid attention in electronics class this week, I'm not kidding, we just went over this stuff!

[Uncle Cracker]

As Joey said, many builder-grade appliances are practically throw-away. By the time you pay a pro to dig out all the junk parts, you could have a new unit, probably of better quality, and a new warranty.

[footprintsinconc]

the unit's is built by Bradford. there is no 800 number on there so that i can call to see if its under warrenty. i think you are right that its probably throw away unit, so no warrenty.

i am a bit confused about the thermocouple and thermistor? which is which. is the thermistor that square box on the outside? if that is what i have to replace, i dont think that is going to be hard. however, where is the thermocouple then, if that is what i have to replace?

i have attached a picture of what the heater looks like, see below.

i just went to hd to see if i could get the square thing on the outside and the plumber guy there (an actual hd employee who seemed like he knew his stuff) said that same thing that joey you just said. he said the new models are sealed and they have a glass bubble in the gas line, if it senses something combustable, it shatter and there is no replacement for it other than replacing the water heater! thats like $500 (what is saw at hd).

now, if i have to buy a new unit. i wanted to know what you guys suggest. another 50 gal upright unit or a on-demand unit. if an upright, should i get the one with 6 year or 12 year warrenty. also what brand would be better than others. this is a first time for me, so all the advice i can get is going to be extremely helpful.

thanks once again for the help.

[Tom Slick]

you water heater only has a thermocouple, no thermistor.

this web page should help you

http://www.bradfordwhite.com/trouble_gas.asp

[footprintsinconc]

thanks tom, will look into this. i was going to look for the owners manual aswell.

so is that square box on the outside the thermocouple?

[Tom Slick]

The thermocouple is heated by the pilot light. the thermocouple uses that heat to create electricity to run the control box on the outside. no heat= the controller not turning on and maintaining the system. its a safety feature to keep from having a gas leak when the pilot light blows out.

I also have a bradford white water heater. the thermocouple wires are the two white wires. the device they are plugged into near the small window is the thermocouple. on mine it has two small screws holding it on.

[Rslaugh]

No, the square box on the outside is the gas valve and control. To find the the thermocouple look where the pilot light flame would be. There should be a cylindrical object about 1/8" diameter and maybe 2" long that protrudes into the flame. When the flame heats this a small voltage is generated back to the valve that says yes there is a flame so it's ok to let gas flow. If the flame goes out or the sensor fails the valve turns the gas off. This is a safety device so that raw gas can not just keep flowing thru the valve without being burned.

There is a metal tube (this is actually a wire with the outside metal jacket providing the return path) which runs from the thermocouple back to the valve and is connected with a small nut. Disconnect the thermocouple here, remove it from the pilot light and take to HD or a local hardware store. Look for a replacement with approx the same length metal tube back to the valve. You can coil the extra up in a loose coil outside the pilot area near the valve. It should cost less than $10. If you have someone come out it will cost anywhere from $50 to $120.

Service manual:
http://www.bradfordwhite.com/images/...als/44943A.pdf

[LCHIEN]

Am I too late? can I make it unanimous? It's a bad thermocouple.

[ragswl4]

It sounds like you might need a new thermocouple. Is that the same as a thermistor?

Ed

Yeah, got my terminolgy mixed up. Thanks for giving the correct name.

[footprintsinconc]

Thermocouple it was! thank you all very much. thank you tom and Rslaugh for the links, they were very helpful since i couldnt find my owner's manual.

the part was for $10 and it was 36" long, i only needed like a 12" long, so the rest of it coiled up outside the hatch. i couldnt get it to coil up inside, the sensor holder next to the pilot was very close to the cover. i have attached a picture of what it looks like now (with the coil outside).

once again, thank you all for the extremely helpful information that is going to be giving us some hot water very soon!!