20 Most Recent Rheem Tankless Hot Water Heater Rtg-74pvp-2 7.4 Gpm - Page 9 Questions & Answers

Check manuel for code

get a different brand water heater

Hi,

If you are not getting a code then that means that the heater is not even trying to light...
The trigger that makes the whole process start is the flow switch.
So, the water is going through but it is not tripping the flow switch to tell the heater to light.
I would say that the first thing to check/replace is the flow switch...


heatman101

Sorry to read about your problem, I hope this helps you out.

your WC pressure is fine it needs 3 and you have 5, can handle 8
The gas company adjust at meter, you have other issues

Check gas solenoid valves for open or short circuits.
Ensure igniter is operational.
Check igniter wiring harness for damage.

THIS IS A GAS PRODUCT, INCORRECT REPAIR CAN CAUSE A EXPLOSION, AND DEATH CAN OCCUR. IF YOU DO HAVE THE PROPER TOOLS SUCH AS MANOMETER AND LEAK DETECTORS, I SUGGEST YOU CONTACT A SERVICE COMPANY

CLICK HERE for your manual.

The P1 error is not in the manual - but it indicates the backflow preventer (check valve) is not fully closing, and should be replaced.

This is a repair for a qualified technician.
Please call them to set up service @ Phone: 1-800-432-8373.

Thanks!

The first thing I would do is to try to attempt to locate the source of the leak. If it's on the manifold or coils then it is probably not cost effective to repair this so you can proceed with diagnoising other problems. Thank you.

is a connection between your controller and the unit disconnect the controller and see if it runs if not then it could be the PCB board. check your wires for bad connections on the remote as well

called Rheem and after giving them the info they are shipping out a replacement board which I can install, hopefully today..to overcome the hot water problem for the short term I disconnected the remote wires at the heater which lets the heater keep producing hot water albeit without the remote...I will keep the old board as backup in case this happens again as there seems to be problems with the PCB

Double check your incoming power supply to the heaters main control panel with a voltmeter.

Inspect the power supply inlet fuses and replace if necessary.

Remove and clean the inlet water supply filter; impeded water flow will not activate the flow switch.

Measure the water flow from each hot-water faucet. You need at least .75 gallons a minute.

Inspect the water flow control turbine. Mineral buildup on the blades will stop it from spinning.

If this is a new installation, make sure that the hot and cold-water lines are not crossed.

Test your plumbing for a cross connection. Turn off the water supply to you heater. Open all the hot

water faucets. If you get a steady steam of water from any of them, you have a cross connection that needs to be remedied. When all else fails, Rheem's customer support team is great. They have always help me with the most technical questions, even on older and outdated products.

if you dont have a remote controller, behind panel in upper right corner there should be a small plastic bag with probes in it...140, 160..just look at about 3 oclock and there should be a place to insert probe.

Hi,

Usually to lower the subcooling you have to add a bit more charge....but that can be effected by many things....

If you are working on a system take a look at this article it goes into the charging procedure and the effects of deifferent things on superheat and subcooling...

http://www.achrnews.com/Articles/Service_and_Maintenance/dd8d6a73c50ec010VgnVCM100000f932a8c0____

You will find the answers you are looking for in this article as it is very comprehesive and goes into great detail...

heatman101

the thermal coupling may be bad!! if the coupling goes bad it will shut down flame. its a safety feature, if gas comes out, and no flame it shuts gas off. the coupling is in pilot light flame and works on the same principle as a thermometer to sense the heat. good luck !!

This is just what I would say for an average family of four during hours of peak usage. You should be okay with a flow rate of twenty to twenty four lpm,assuming you have rapid enough recovery. This is based on one shower at a time and not running dishwasher or clothes washer at the same time.If you are using hot water from multiple fixtures then increase accordingly.Hope this helps. Thanks

I am a free answerer, and I specialize in giving you resources for free
The paid answerers may have a person who knows your product and the error codes
The manual will also have the error codes if that applies to your model.
The person who installed the unit will also know the repair procedures.
Each day I see 20-25 unanswered questions about tankless water heaters.
The number of questions shows the complexity of the machines, and the inability of the manufactures to take care of their customers.
Absolutely I believe the promotion of tankless products does not match the reality.
The manufacturer will refer you to the installer.

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

http://www.rheem.com/products/tankless_water_heaters/
The link above goes to Rheem tankless water heaters
Click on a product and it opens a page showing many tankless models
Click 'more information' and another page opens with spec sheets and other pdf
Not surprisingly there are no troubleshooting steps or troubleshooting flowcharts
There are plenty of ways to buy a tankless
There are not many ways a do-it-yourselfer can fix a tankless

Hi,
Does it give you a flashing code as to why it went into lockout?
You should look for the flashing LED and then check the book for the reason.
It is probably a pressure switch or a dirty flame sensor....if the gas press. is alright...
Check the venting to make sure it is open and in good shape also...

heatman101

See image larger

-Tankless water heaters are susceptible to lime build-up if not de-limed each year.
-Hard water will clog pressure-sensor and cause failure within 2 years if filter and softener are not working.
-Water flow and water pressure sensors inside tankless are succeptible to hard water deposits.
-Low water pressure from clogged pipes to municipal water problems to water well pressure valve can affect tankless burner
-Low-flow shower heads may not engage burner.
-With tankless-gas water heaters, sensors inside combustion area detect when incoming air flow is not adequate ... inspect inflow
-Your manual probably has a troubleshoot section.
-The manufacturer will refer you to installer.
-If you self-installed unit, that will void warranty to my understanding.
-There are water heater forums 1 2 3 4
-There are plumbers who will each have a different opinion
-There are Fixya experts who get paid to tell you the above.
-And there are local plumbers who are authorized dealers of the brand of tankless who get paid to fix them