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Mike R.
Mike R., Plumber
Category: Plumbing
Satisfied Customers: 2852
Experience:  20 years of plumbing experience, including high end homes and service work.
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The plumber717, i am having the problem (code11) on my

Customer Question

hi the plumber717, i am having the sam problem (code11) on my Rinnai R75LS
Submitted: 1 year ago.
Category: Plumbing
Expert:  Mike R. replied 1 year ago.

Hi my name is ***** ***** I have been in the plumbing field for 20 years. I will be glad to help you today. Is this a new installation or existing? If it is existing, how old is it?

Customer: replied 1 year ago.
the unit is about 5 years old. The igniter will not light
Expert:  Mike R. replied 1 year ago.

If you run a tap does the hot water pressure seem less compared to the cold? Have you ever done any maintenance on the unit?

Customer: replied 1 year ago.
I don't know what you mean when you say run a tap. I have never done any maintenance on this unit. It belongs to the church and I just wanted to try to fix it.
Expert:  Mike R. replied 1 year ago.

Gotcha. If you run the water in a sink or shower does the water pressure seem less when running hot water compared to cold?

Customer: replied 1 year ago.
No, they both seem the same.
Expert:  Mike R. replied 1 year ago.

Is this natural gas or LP? Is it metered gas or is there a tank that is refilled and has the tank recently been filled?

Expert:  Mike R. replied 1 year ago.

Sorry for all the questions.....there may be a few more but we will work it out.

Customer: replied 1 year ago.
It is natural gas and it does not have a tank for refills
Expert:  Mike R. replied 1 year ago.

Is there a controller hooked up to it? If so will you disconnect the controller and try it then? Is there any clicking or does the fan turn on when running the hot water?

Customer: replied 1 year ago.
I hear something trying to start and I hear a fan running
Expert:  Mike R. replied 1 year ago.

If you release water from the temperature relief valve, does that water get hot?

Customer: replied 1 year ago.
I did not try that. Is that located on the bottom left of the unit? I don't think it would get hot, there is not a flame
Expert:  Mike R. replied 1 year ago.

There is not a flame unless the water is running. There is not a pilot flame, there is a spark electrode that sparks the burner from water flow. When opening the temperature relief valve does it click or get hot? The temperature pressure relief valve is off of the hot water piping with the spring lever and a pipe coming off of it and that pipe should go to a floor drain or outside.

Customer: replied 1 year ago.
Okay, I know which pipe you are referring to. When I run the water the I am looking for the spark electrode to spark but It does not spark.
Expert:  Mike R. replied 1 year ago.

To be clear, you have opened the temperature relief valve and while running there is no clicking and the fan turns on briefly then the error code?

Customer: replied 1 year ago.
I did not open the relief valve at all. The fan runs and there is no clicking and yes then I get the error code 11
Expert:  Mike R. replied 1 year ago.

Do you have a multi-meter and are you familiar with testing voltages? Will you please try opening the temperature relief valve and listen for the clicking while it runs for a few seconds out of the relief valve?

Customer: replied 1 year ago.
I am familiar with testing voltages but I am not at the unit now and will not be there until tomorrow.
Expert:  Mike R. replied 1 year ago.

So, if there is no clicking when releasing water from the valve then check if you get voltage to the spark electrode when doing so. If yes then the electrode is faulty. Also check the dip switch settings are correct and test gas and water pressure. Also flush the unit to clear any blockages in the heat exchanger. Once the dip switch settings are confirmed get the gas company to confirm that the gas meter is correctly sized and check that the gas supply pipe is correctly sized. The supply pipe for gas should be minimum 3/4" rigid pipe and minimum 1" flexible pipe.

Customer: replied 1 year ago.
Okay, right now the gas line is 3/4" flexible pipe. Should I change that to either one inch or change to 3/4" rigid then start over?
Customer: replied 1 year ago.
I am sorry but I have to go to bed now. Will I be charged for this session?
Expert:  Mike R. replied 1 year ago.

That would make sense. The flexible pipe inner diameter is smaller than rigid pipe. The restricted fuel and likely an incorrect dip switch setting causes the spark electrode to spark more often than it should and causes increased wear on the electrode and now it's worn out. Yes replace the pipe with the proper size and check the dip switch settings. One switch setting is for elevation so Google your elevation before you go. Be sure to have the gas company size the meter too. It's free and if a larger one is needed that's free too.

Customer: replied 1 year ago.
Should I replace the electrode too?
Expert:  Mike R. replied 1 year ago.

Not without testing the voltage. If there is no voltage to the electrode when opening the valve then there may be an issue with the control board. If you are not familiar with testing electronics with a multi-meter then that may be the time you want to call Rinnai. That could be pretty expensive to replace and often finding a board on your own will be an issue too. Better to let the certified people take over at that point. It should be covered under the warranty also.,,,,although I am unsure if the incorrect installation voids the warranty or not. It really does sound like the spark electrode is fried and was caused by poor fuel delivery.

Expert:  Mike R. replied 1 year ago.

I haven't heard from you. Was the information I provided helpful?

Expert:  Mike R. replied 1 year ago.

Did you find the information I provided helpful?