How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Todd Your Own Question
Todd, Plumber
Category: Plumbing
Satisfied Customers: 368
Experience:  Union Plumber 28 years of service work, and new homes.
Type Your Plumbing Question Here...
Todd is online now
A new question is answered every 9 seconds

I have a AO Smith Powershot FPSH 50 260 water heater. It

This answer was rated:

I have a AO Smith Powershot FPSH 50 260 water heater.

It heats up and cools down on its own does not stay hot all the time. I can periodically turn the blower switch on and off but this does not always work. In the morning it wil be cold and can be hot at night?
Chat Conversation Started
Hauserplb :


Hauserplb :

My first question is, what size is the vent piping, how long is it (need to be fairly exact) and how many elbows (90's and 45's)?

Customer :

2.5" PVC, 2 90's, 1 45 approx 140" of pipe

Customer :

it is running right now and seems to be venting fine

Customer :

the LED indicator also flashed 6 times repeatedly

Customer :

the manual has 9 options for check repair and 3 options to issue

Customer :

testing to make sure chat is still going

Hi, and Welcome to Just Answer. My name isXXXXX will do my best to answer your question to the best of my professional ability.

its seems you haven't been giving a answer yet so let me get that for you , Is the fan or blower motor kicking on when the tank lights up? it should and if the exhaust fan is not blowing then the tank will shut down and go into safe mode. How old is the heater ?

a bad thermostat could also cause this , if its getting a false reading then it will cause the heater to act up and not get hot when you need it then go cold.

If the gas Orifice gets clogged up then this could also happen .

or the thermo coupling could also be bad and causing this problem.
Customer: replied 6 years ago.

the blower turns on.


Is there a way to test the many "or's"?

well this is if you have multi volt meter, and you know a thing or 2, you said it flashes 6 times fast ? what did the manual say about that ? how old is the heater?
140 feet is kind of a long run for the vent , but I've seen longer. If you don't know the year the tank was made it should be near the serial number.
Customer: replied 6 years ago.

I read the manual but figured I would try this site for better advice

7 years old

6 Flashes System Lockout.

1. Reversed polarity in 115 volt power supply.

2. Heater/burner not properly earth grounded, check pin

3 on wire harness plug (valve end) to burner

4 trials for ignition failed or 4 loses of flame tube for 115 volts, check ground path to burner.

occurred before set-point was reached.

3. Ground fault interruption (GFI) breaker causing

intermittent operation, try non-GFI outlet.

After 1 hour "soft" lockout, SmartValve control

4. Flame sense rod dirty or incorrectly positioned.

will initiate a new ignition sequence if the call

5. Vent system length exceeded, too many elbows,

for heat is still present. (SmartValve can cycle blocked exhaust/intake switch opens after light off.

this way indefinitely.)

6. Flame sense/HSI wiring condition/connections.

7. Low or no supply gas pressure.

8. Fluorescent lighting on same breaker as heater.

9. Damaged, defective, or incorrectly positioned HSI.

well if your getting power to the board, and you are getting gas, and the fan is running you said, then it might be the thermo coupling or thermo stat, but could be the flow sensor as well, if the tank is taht old then its on its last couple of useful working life and thats why its acting up. If you call the manufacture service hot line they will be able to tell you what part it is by the number of flashing lights , they also will be able to send you a replacement part, or they might even say that the heater is in need of replacement. And last of all the circuit board it self could of taken a dive for the deep end and it could be just a electrical problem.


if you go here and fill this out they will contact you back.

Customer: replied 6 years ago.
Relist: Answer quality.
I thought the last set of answers were generic and I already have the manual and know what it says. The answer did not seem knwledgeable to my specific problem.
in person a professional could test the unit , but not over Internet, contacting the manufacture is you best bet its too many things that could be causing this and i gave you the list of what it could be.
Clean the flame senor, which is right next to the igniter. This is a rod about 1/8 diameter . Use a piece of steel wool to clean this rod.
Todd, Plumber
Category: Plumbing
Satisfied Customers: 368
Experience: Union Plumber 28 years of service work, and new homes.
Todd and other Plumbing Specialists are ready to help you

I will also agree that when these water heaters get older (7 yrs qualifies) they do start acting up. The components start being more sensitive to the conditions and error codes become an issue. Your venting distance is one that can be causing this.


However, you may also have a deteriorated dip tube. This tube is inside the heater on your cold side inlet and introduces the fresh cold water to the bottom of your tank for heating. Remember, heat rises, so when you tank a shower the hot water thats been heated exits the top and new water enters the bottom for heating, mixes with the already hot. If no cold water is introduced for say 1/2 hr. the tank has the opportunity to catch up to its SET temperature. Typically, in the A.M. the first thing we do is use the toilet, wash hands, maybe even brush our teeth. Now the cold water is really cold. turn on the shower, and without the dip tube, the cold water is right at the top of your tank and this is what you get for your morning shower.

Related Plumbing Questions