Ruud gas hot water heater shuts off and needs reset multiple times and will only run continiously for less than a day.

Shutting Down and Gas Hot Water Heater
There are four steps to properly shutting down a gas hot water heater:
(1) For working on water pipes or draining the tank, turn the gas valve control to pilot.
(2) For any other work on the hot water heater, turn the gas completely off.
(3) Cool down the water inside of the tank.
(4) Shut off the cold water supply to the hot water tank.
(5) Open a hot water faucet somewhere, (preferably above) in the house.
Step One - Setting a Gas Valve On 'Pilot'

The water heater gas valve is located toward the bottom of your water heater just above the burner chamber. On the top of the gas valve that has various settings on it. The three main settings are 'OFF', 'Pilot' and 'ON'.
Turning the dial to 'Pilot' will shut the gas off to the burner without shutting off the pilot light. This setting can save you the trouble of having to light the pilot again when you are done. This setting should not be used if you are doing any work on the burner assembly or the gas line. It is suitable to use when you are draining the tank or working on the water lines.
Step Two - Turning the Gas OFF

The safest thing to do whenever you work on your gas hot water heater. Leaking gas can explode and is quite dangerous.
First turn the dial on the gas valve to 'OFF'. Turning the gas valve to 'OFF' does not completely shut off the gas. There is a ball valve on the gas piping next to the water heater. This valve should be turned 90 degrees until the handle is perpendicular to the pipe.
With the gas valve shut off, the gas is completely turned off and the water heater is safe to work on.
Step Three - Cool Down the Water
This is an important step. Water that is directly out of the gas hot water tank can be very hot and scald or burn you. Run and considerable amount of hot water through one of the fixtures until the water is just warm. Do not mix it with cold water, run it pure hot. The cold water running into the tank will dilute the hot water and reduce the temperature.
After the water has cooled down, it is safest to work on the water heater.
Step Four - Shut Off the Cold Water Supply
Do not shut the water off if you have not turned the gas going into your gas hot water heater off. If the water continues to heat inside the water heater after the water is shut off the heater will build up too much pressure. If you are sure the water is off, you can turn off the cold water supply.
Step Five - Open a Hot Water Faucet
Opening a faucet will prevent the water heater from developing an air lock. Any attempts to drain the water tank will fail if a faucet is not open to provide air.
It should now be safe to work on your hot water tank.
Step Five - Draining a Hot Water Tank
Most repairs on a gas hot water tank can be made without draining the tank. There are, however a few exceptions that must be noted.
Removing or replacing a gas valve will require the tank to be drained. This part threads directly into the lower portion of the tank. Another activity that requires an empty tank is flushing out the sediment. Clearing out water heater sediment on a annual or semi-annual program is a good maintenance program. Draining the tank is a chore, but the steps required are also required for the sediment flush, so it is really not any extra work.

It sounds like the thermostat that operated gas valve is failing or the gas valve is bad. This is a repair left to professionals. Now I would price a new heater and install it myself. Repairing older heater is not a good idea, the rest of the heater is old and will fail.

Unless you are using a tankless hot water heater, there is a limited amount of hot water available in the tank. Electric and gas water tanks need time to recover after use, and if you are using heavily, it can exhaust the available supply. That said, there are a couple reasons why you may have less hot water than seems normal. In both electric and gas water heaters, silt can form in the bottom of the tank. This will build up over time and displace water. It also reduces the heating efficiency of gas units. There is a drain valve on the bottom of water heater tanks to allow for purging of this silt periodically, but few ever do it. You could also have, in the case of an electric hot water heater, a bad element or thermostat. Most electric heaters have an upper and lower element and thermostat. If one fails the other will still work, but the water takes longer to get hot and will deplete faster.

Have you cleaned the air intake screen located below combustion chamber?
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html

http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

http://www.thetankatwaterheaterrescue.com/forums/forum3/

Gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Thanks for stopping by:

A2 error on your Bosch water heater means "Fault in the flue gas limiter"

This can be caused by several things:
The gasket on the flue gas collector may be dislodged/leaking.
Check/Remove/Reseat the gasket.
It will not reset until about a two hour cool down.

Also - check the overheat sensor fuse wire - it may have gotten hot and melted the jacket and/or been dis-colored.

Finally - there is a retrofit kit "repair" that can be obtained by calling them directly.

1-800-642-3111 and request the "FLUE GAS LIMITER RETROFIT", Part NO. 8-700-400-032. This should solve many error code situations and get you on your way again.


Thanks for using FixYa!!

Your tank is rusted out and needs to be replaced.
Link below is a troubleshoot for leaking water heater.
http://waterheatertimer.org/Leaking-water-heater.html

Protect yourself first:
If your tank is rusted, there is danger of rupture.
My friend welded his leaking tank, but he assumes the risk.
Ruptured tank can cause massive damage and water runs until it is shut off.

Hot water tank is under pressure because hot water expands and pushes against tank wall.
Turn off water to tank.
Turn off power supply:
Electric: turn off circuit breaker.
Gas: rotate knob to pilot so pilot stays lit but burner will not fire. To turn back on, rotate knob to ON.
Open hot side bathtub valve and relieve pressure on tank.

You can limp by with rusted tank by turning water heater on when hot water is needed.
Shower uses 5-9 gallons hot water
Bath uses 12-15 gallon hot water
Ordinary gas heater makes 41 gallons hot water per hour
Ordinary electric heater makes 20 gallons hot water per hour.

I buy water heaters at Lowes, Home Depot, Ace.
Look for scratch and dent models.
Buy drip pan for water heater.
Wrap electric heater totally with insulation except TP valve.
Buy new flexible connectors for water lines.
Offer 15% less than marked price on tank, because the store makes money on additional items.

> Most people can install their own electric heater since you just connect water pipes and electric wire, and it's done. Read link below since there are tips that help you buy and install electric.
> Generally people are nervous about installing gas water heater, so step-by-step instructions are shown on link below. Remember gas line is under less pressure than water line, so if you can install a water pipe, you can install gas line to water heater with crescent wrench, and soapy water to check for leaks.
How to install gas water heater:
http://waterheatertimer.org/How-to-install-gas-water-heater.html

Add a comment for more free help.
Also take advantage of fixya phone service.
For a price, fixya expert speaks with you over phone while you work on water heater, or any do-it-yourself project.

A leaking water heater cannot be repaired, assuming it's the tank leaking and not nearby water pipe.
http://waterheatertimer.org/Water-heater-leaking.html

First thing is to protect your property from catastrophic tank failure where tank ruptures and water runs until it is shut off:
Tanks are under pressure when they are hot.
Close cold water shut-off located above tank.
Turn control knob to 'pilot' so pilot is lit but burner will not turn on.
Open hot side on tub for few moments to relieve tank pressure.

Now your property is safe.
You need a new water heater.
In mean time, gas water heater makes 41 gallons hot water per hour.
Shower used 5-9 gallons hot water.
Bath uses 10-15 gallons hot water.
You can turn on water heater for short stretches and limp by until you get a new heater.

Steps for installing gas water heater:
http://waterheatertimer.org/How-to-install-gas-water-heater.html

If you run hot water thru the hot side of the kitchen faucet does the water heater come on and burner run to provide hot water or does it just start then shut back off. If it starts then shuts back off I would turn thermostat up to a higher temperature. If it will not go any hotter you may need to rplace the gas valve.
Make sure your burner is clean and has a good quality flame .if not clean burner andcheck gas pressssure ti your water heater burners.
I do not know of any valve then normal so I can't help you there. Good luck Thank you.

Hello,

Based on gas prices, often gas hot water heaters can be a more cost-effective option than electric models and preferred by many homeowners. However, gas hot water heater models can have their own set of problems that differ from electric versions. You will not find it difficult to perform some basic troubleshooting to resolve an issue with a gas hot water heater.

Instructions

1. 1 Determine if the gas supply has been shut off. No gas will cause the hot water heater to stop producing hot water. Turning the gas supply back on should be your first troubleshooting technique.
   
2. 2 Check the pilot light. If you are experiencing no hot water, the pilot light of your gas hot water heater may have distinguished. Turn off the gas source and place a match over the pilot light tube to relight it.
   
3. 3 Adjust the thermostat of your hot water heater. If you find that the hot water runs out quickly or does not get hot enough, you may need to set the temperature of the gas hot water heater higher. Typically, set the dial between the medium and hot setting for adequate hot water.
   
4. 4 Inspect the gas hot water heater. The burner orifice and flue can both become clogged on a hot water heater. Turn off the gas and use a wire brush to clean out any debris that may have become lodged in these sections.
   
5. 5 Ensure that all the burner access covers are in place. If the pilot light will not stay lit, it could be due to exposure to drafts.
   
6. 6 Flush the tank. Certain deposits can build up over time when using a gas hot water heater which can cause the tank to produce a banging noise. To flush it, turn the heater off and open the pressure relief valve and drain valve on the water heater. Use a hose to flush water through the system until the hose runs clear.
   
7. 
   

Thanks.

your unit is undersized or you do not have enough gas supply to run the unit properly.
If you have to many water features running or you have to many gas items turn on at the same time it can cause problems.