hot water heater trouble
 

Any plumbers out there? My A O smith heater won't stay lit anyone know how to fix this? Heater is only 2 years old.

It might be the flame sensor. Remove it and clean the metal rod with a little emery paper.

Had the same trouble with one of my boilers and it was the thermal coupler that was shot.

I read that it could be the thermo coupler. But the unit is only 2 yrs old, do these things break down that quickly?

Yes they can burn out within a couple yrs depending on how often the water heater kicks in. The one for my boiler was only $25 and I was able to replace it with ease. If anything I think I would rather replace a thermal coupler every couple yrs then something more expensive.

If I'm not mistaken. A two year old water heater is sealed combustion with a flame arresting intake screen on the bottom/side (if it is naturally aspirated(metal chimney)). On the right of the burner viewing glass there's a manual limit switch. Check that. If I'm way off base, post the model #.

+1 on the thermocouple, most hardware and big box stores sell them, pretty easy to change, just get the right length

This is a sealed unit with plastic tubes.

Power vented then. Clean your flame sensor. They usually suck to get to.

Does it try to turn on, then shut down?

Mine did this once, i took out the thermal sensor and cleaned it with emery paper, put it back and it worked fine ever since. As TimT stated, it is a rod held by a couple screws

Hey Jason,
check to see if the vent or intake has closed off do to the condensate. I assume the tank is a mid eff. and has been side walled? With the sudden drop in temperature over the last week, it may have chocked off the intake or vent. If they are clear, probably the thermocouple. LMK, if I can help.

What do you mean by side walled?
edit - This has happened last year when it was really cold.

if it is a power vented unit then there will be 1 or 2 pressure switches that determine if the vent is venting properly, one of the most common problems is a blocked condensate drain that allows water to backup in the pipe causing a blockage in the vent which causes the unit to shut down, in this case, the unit ussually starts briefly and then shuts down

Jason,
Give me a call, I'm at home right now with a sick kid but can probably walk you through it.

I found the parts list and I need some help identifying the flame sensor.
I believe it is part# 25 called fv sensor.
http://i379.photobucket.com/albums/o...hgpdmanual.jpg
http://i379.photobucket.com/albums/o...gpdmanual2.jpg

does the hot surface igniter glow red hot while the unit is trying to ignite?
the FV sensor is a Flamable Vapour sensor, it will lockout the unit if vapours are present, gas vapours, paint vapours, etc.

When I turn on the tank the fan turns on, glow plug heats up, burner ignites for 5-10 min. and then it shuts off. It cycles twice then turns off and goes into vacation mode.

is the fv sensor the metal rod that has to be cleaned?

Now I'm confused, my hot water heater is working again.
Seems to be related to cold weather because it was -30 when it stopped and today it's -18 and its working .

no, the FV sensor senses the pressence of flammable vapours, a flame sensor is a metal rod that will produce a voltage when heated, detecting a flame

I would suspect a problem with the vent or the pessure switch for the vent, extreme cold and or high winds could cause an abnormal pressure.
The pressure switch is # 27

Is the water heater running on natural gas or propane?
propane pressure is affected by the cold.

could have been with the extreme cold in Edmonton might of had a ice build up blocking part of the exhaust vent.

I checked for blockage and there was none that I could see and it's a natural gas heater.
I'm not sure what going on because it quit working again. I had to use the shower last so I found out that the heater wasn't working the cold way. Going snowboarding today so I'm going to deal with this when I get home.

the water heater must have a flame sensor, it must be part of the hot surface igniter therefore not shown on the parts list,, located at the bottom of the heater beside the burner, it should be a rod a couple inches long that will be hit by the burner flame when the burner is lit, that will be need to be cleaned with some sandpaper.

What do mean by vacation mode? I agree that a o smith gas valves are junk, but resetting temperature is not something they do. The LEDs are telling you a code, that code should be in the book. Start there. Here's a manual for the GDP

winged fish thanks for the link.

The heater has started again since I was gone but if I remember correctly it was error 6. This is the quote from the file for the code.

"Ignition/flame failure.
The gas control valve has reached the maximum number or retries (3) for ignition and is currently locked out for one hour.
Cycle the power to the water heater off and on to reset.
1 Gas supply is turned off - pressure is too low.
2 Ensure the flame sensor is clean - use fine steel wool to clean the flame sensor.
3 Manifold gas pressure to the burner is too low.
4 Check igniter assembly plug and the socket on the bottom of the gas control valve for good connection. Replace igniter assembly if the plug is worn or damaged replace the gas control valve if socket is worn or damaged.
5 Replace igniter assembly.

If it is in fact that code, then dimes to dollars it will come back soon and you need to clean the flame sensor. Do yourself a favor, if it has the torx screws on the cover, take them out and chuck them as far as you can. Replace them with something a normal person will have a driver for.