I have an AO Smith, Gas Hot Water Hot Heater, Model FPS 40 226. It has a power vent (fan) out the side of the house. It is 9 years old.
The last few months I have noticed that the water is not as hot as it used to be (it is on the hottest setting). After reading this board, I drain the heater to flush out any settiment, but that did not help.
Last night I had no hot water. The first thing I checked was the pilot light, it was lit. I turned the thermostat from hottest to hot - no effect. I then turned the gas control knob (may not be proper term) on the thermostat from On to Pilot and then back to on - the burner fired immediately and I had hot water.
I Ihad the same problem and solution this morning.
I think I have a bad thermostat - agree?
I have not had a chance to check prices yet, but in general is it worth replacing the thermostat on a 9 year unit of should I replace? Thanks....
Hello: aashby
How turning the control knob from on to pilot and back to on can effect the burner turning is amazing but likely did work in your instance. As evident by the results.
Turning the control knob simply opens or closed a port through which burner gas can flow. Does not turn burner on or off. Unless I am missing a point or aspect here. That's Possible.....????
What likely happened is a slight jarring of the thermostat resulted, effectually allowing the internal gas valve to open. Once that happened the burner fired up.
If the internal click on sensing element is sticking, the condition described can result. T-Stat control unit replacement would solve the problem.
Is it worth replacing you asked. Most like yes. Not too expensive nor difficult to replace when done correctly. Worth replacing is a personal determination based on the condition of the water heater, ones immediate need and financial situation at the present time.
Be sure the power vent fan is freely able to start and operate. All systems in that circuitry must be good clean connections and in proper working order. Part of this system effects all others.
What kind of thermostat is it? Electronic or the regular one with a mercury switch?
Maybe the pilot light is not heating the thermocouple enough to let the gas through the gas valve.
So, are you saying that what I most likely need to replace is not the piece with the gas control know and temperature control knob? I tried looking up the parts on the A O Smith web site, but I can not find my exact model. I can find parts for the FPSE-40, but mine reads FPS-40. Maybe it is just an older model?
I can find a thermostat listed for the FPSE (Part #181705). Do you think this is what I need to replace?
Looking at another section of the A O Smith site I see White Rogers Temperature Controls - part numbers 23736, 180193-4, 180193-5, 182791-3. The picture of these lok like what is on my heater.
p.s. The blower works fine.
It depends on what is causing the problem, I would get a professional to troubleshoot it.
Go to www.hotwater.com probably same site you are at.
Contact the rep in your area for A.O. Smith; they keep all the parts on the trucks, and makes simple work of troubleshooting.
You can almost all the info you need on A.O. Smith water heaters on this site.
http://www.freep.com/money/consumer/...3_20000903.htm
It's your dip tube.
A dip tube is a plastic pipe the inserts deep into the tank, and which - over time - deteriorates into fine plastic particles. I know, the particles are all through my house and faucets. My hot water tank has been acting like yours too.
What you do is either have a plumber replace the dip tube or do it yourself.
There was a class action suite against the tube manufacturer that ended in January of 2001. But the problem started in around 1993. I wasn't notified by my installer or the company (AO Smith) that there was a problem so the cost is mine. But it's better than buying a whole new tank.
The web address will take you to more info on dip tubes and the suite.
Tags: replace, thermostat, control knob, burner fired, model find, need replace, pilot light, power vent, Smith site, thermostat from, worth replacing
