On demand, tank less water heater

If you are installing new tankless in place of 40 gallon gas water heater, then you CANNOT use same vent pipe.
You must use larger diameter pipe that is specified by instruction sheet, and the pipe must be approved plastic or stainless steel to avoid corrosion.
The vent pipe must also have a condensate trap to catch acidic water that drips back down the vent pipe.
The reason is that tankless burn more gas than regular tank-type heater... because tankless must raise temperature quickly as water passes in a pipe.
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Gene

Water Heater Timers Save Money

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

Add tempering tank.
Tempering tank made from old tank-type water heater, or small tank heater will passively heat incoming water.
http://waterheatertimer.org/Tempering-tank.html

This works because tankless can only raise temperature so many degrees. If water is very cold, tankless cannot keep up, so the sensors shut down the unit.
Passively preheating water... or using a small tank connected to power can preheat water enough so tankless works.
Also delime tankless each year will help remove natural scale that builds up inside tankless heat exchanger.
http://waterheatertimer.org/How-to-delime-tankless-water-heater.html

Gene

Water Heater Timers Save Money

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

If tankless computer is less than 5 years old, then call Rheem for local technician qualified to work on this type of computer that heats water.

If tankless is older than 5 years, then replace with tank-type electric water heater for $285 from Lowes.

Avoid Rheem, Richmond, Palmoa, GE water heating products since this company does not post service manuals.

Choose AO Smith, American, State, craftmaster, Whirlpool etc.

Gene
h

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

I can offer resources:
1) Open following links for possible help.
http://waterheatertimer.org/pdf/No-Error-Code.pdf
http://waterheatertimer.org/Crossover.html
http://waterheatertimer.org/Low-hot-water-pressure.html
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

2) As a note: When the motherboard on a computer or phone needs replacement, most people figure the device is about used up. The same is true for tankless.
Despite promotions claiming longer life, tankless warranty is not longer than warranty for typical tank-type water heater.

3) Fix most tankless problems yourself, same day, for $300-400
http://waterheatertimer.org/How-to-install-gas-water-heater.html

Take a moment and rate answer for accuracy:
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

Service technician is probably best bet for troubleshooting all possible causes from plumbing leak to burner assembly needing cleaned to blower problem to bad gas control valve or tripped ECO, or combination of things listed above.

The intelli vent controller has error codes.
Open link for images, error codes and sample manual.
http://waterheatertimer.org/How-to-adjust-water-heater-temperature.html#Intellivent

I think the Kenmore is a Rheem product, but the market changes very fast.
Intellivent control indicates that water heater has a blower on top of heater that communicates with the gas control valve to coordinate combustion.
Rheem recommends the burner assembly be cleaned no less than once a year by trained service technician who has the tools and experience.

Newer gas water heaters, both tank and tankless are maintenance heavy because of energy and safety standards, and because of new electronic controls. Tankless require more frequent attention.

If problem is going to cost more than $330, then install new gas water heater yourself from local box store. I recommend avoiding electronics, and blowers, and tankless so you can hold down costs and maintain the unit yourself.
http://waterheatertimer.org/How-to-install-gas-water-heater.html
Water heater electronics and energy factor are good initial selling points, but all costs are energy, and repairs, service and parts of more sophisticated machines can cost more than the $1 to $8 saving you can expect under best circumstance.

Upvote the help.
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

You posted under typical Rheem tank-type electric water heater, but don't say what service you want to perform.
Listed below are typical actions one takes with electric water heater:

1) Flush tank each 6 months to prevent sediment.
http://waterheatertimer.org/Clean-sediment-out-of-water-heater.html#flushelectric
2) Inspect and replace anode rod.
http://waterheatertimer.org/Replace-anode-rod.html
3) Test electricity from breaker box to water heater
http://waterheatertimer.org/Test-electricity-to-water-heater.html
4) Troubleshoot electric water heater
http://waterheatertimer.org/How-to-troubleshoot-electric-water-heater.html
5) Clean sediment out of water heater
http://waterheatertimer.org/How-to-clean-sediment-out-of-electric-water-heater.html
6) Save money
http://waterheatertimer.org/9-ways-to-save-with-water-heater.html
7) Do it yourself information
http://waterheatertimer.org/Do-it-yourself-water-heater-timer.html

Add a comment for more free help.
Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

BOSH AQ 250 On demand propane water heater ran out of propane, got gas now, but get EC flashing on the display and the unit won't fire? Lost manual, any suggestions. Thanks, Jim

I had the same problem with my Paloma a year and a half after installation...contacted Rheem customer service (800-432-8373) and they recommened a local installer in my area. The technican diagnosed the problem as the "flow control valve"; he managed to get Rheem/Paloma to cover the part under warranty...I only had to shell out the money for the install.

An on-demand, or tankless, water heater is a system for heating water as it passes through the pipes, usually very near the point of use. Traditional tank water heaters bring the water to approximately 140 degrees Fahrenheit (60 C), in order to ensure the water supply lasts long after the heater turns off. Since this is obviously far too hot to be pumped out of a shower of faucet, cold water is added to the mix in the pipes. Coupled with the loss of thermal energy over time, the average tank heater has an efficiency of approximately 80%. On-demand water heaters have a number of advantages over their tank-using counterparts. While tanks often degrade over time and begin leaking, the apparatus used in an on-demand water heater is much less susceptible to the burdens of age, and will often outlive the house they're installed in. The amount of energy used is a fraction of that used in a tank water heater, due to increased efficiency and a much smaller window during which a heating source is in use. While tank hot water heaters can, and often do, run out of hot water after a number of showers, on-demand heaters provide a never-ending supply of hot water, ensuring that warm water is always available when needed. A tankless water heater can cost between $500 and $1500, and they most commonly use either electric or natural gas energy to heat the water. Most mid-sized households report an energy savings of approximately 25-45% for a gas or propane heater, and up to 50% with an electric heater, over using traditional tank heaters. Water is usually set to a maximum temperature of 120 degrees Fahrenheit (49 C), though many heaters allow for custom setting of the maximum temperature via remote control. Outflow rates range from 8-14 gallons (30-53 litres) per minute. Installation for most tankless water heaters is incredibly easy, involving simple plumbing. In the case of electric heaters, all that is required for a fuel source is to plug the heater into an outlet and begin heating your water. Some modern on-demand water heaters can incorporate a solar preheating system. This system uses a traditional solar heating system and tank to bring the water nearer to the desired temperature, saving substantial energy use in the final on-demand heating. A solar preheating system costs between $500 and $800.