Rinnai E110CRP Error : E 02
Recently, my Rinnai E110CRP started to fault with the error code “E 02.” This error code indicates “no flame-forming.”
I checked the AC voltage at the ignition unit and found a constant 12 volts AC when the burner is on, and 0 volts when it is off. I’m not sure what values I should expect.
The propane company recently filled the tank — it was about 30% full before they topped it off. This issue started around the same time. I’m not sure if the two events are related or just coincidental.
I am trying to diagnose the problem. My next plan of action is to check that I have 8–14 inches W.C. (water column). This is where I need your assistance setting up the test. In photo 0949, I see an “OUT” port, and it seems this is where I should attach my manometer to retrieve a reading after opening the flathead screw. The screw below it has what looks like “MIN” written next to it. Is this the screw I would use to adjust the W.C.?
I also tried testing the ionization current but wasn’t sure how to properly set up that test. I placed the meter in series, but the instructions were a little confusing. The symptoms seem to match what the documentation describes: the heater turns on but shuts off after a while. In my case, it shuts off after about 1 hour and 20 minutes.
The heater will stay on if there is a request for D.H.W. (domestic hot water), but it goes out after about 1 hour and 20 minutes when it’s heating the floor via the thermostat. I also noticed that the flame starts off nice and blue, but decays to a reddish color when it’s about to fault.
When testing the W.C., should I have the water heater operating under a heating request? Also, when conducting the ionization current test, I followed the instruction to “STEP-button once until 1 is shown alternately 1 and OFF will be shown.” That part worked, but afterward, no maximum value appeared. This is another area where I need your assistance.
Thanks in advance.
Comments
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Are you a homeowner or technician?
You have you leads in the wrong ports of your meter and the dial is set for the wrong measurement scale.
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I am the home owner and I am measuring the volts AC. It is 12 volts. It is in the correct ports for measuring volts. The dial is on the wave with the volts. That is for AC.
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I think the meter confusion is in the picture @lindylex is measuring the AC voltage at the Gas valve, not the flame ionization current, which would be DC microamps.
As near as I can tell from the vagueness of the manual, the Gas valve should have 24 VAC across it.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
That is correct. Sorry for the confusion yes that is what I am measuring the gas valve voltage. I am not sure what I should expect when it is operating. Currently I get a constant 12 volts A/C. The ionization current test is a bit confusing and I would like to clarify so I can properly test it. I would also like some clarification on the W.C. pressure test procedure. If the gas valve should have 24 volts across it then this test feels like it might reveal some failure. Is this why you think I should be seeing 24 VAC "…The minimum gas pre-pressure during the start must be a minimum of 7"W.C.(17 mbar), check the 24 Volts in the gas during ignition block’s open position" ? That is from the manual page 73.
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Thanks and I knew where to place the leads for the microamps ( µA ) test. My question is with procedure 10. It does not work as printed.
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" procedure 10. " ???
As far a the flame current procedure, what I get out of it, is they want the test done at full load or maybe maximum flame, to possibly record the maximum value . There should be flame current anytime the flame is present.
As far as the 24 VAC at the gas valve, yes page 73, also Page 48 and 49. Not sure what they mean by " 24V= ".
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
' "
procedure 10." ??? ' The tenth instruction starting from the top on 12.4. This does not work when I get there.I will check the other electrical components to see if they read the voltage values indicated on this wiring diagram. Thanks for the explanation. Page 48 is much clearer now. If I get values that match this chart I will know I am looking at a possible issue.
Any insights on the W.C. test?
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I don't see any illustration or mention of a gas service port. Just gas pressures at the gas valve, inlet pressure port mentioned below.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
" The tenth instruction starting from the top on 12.4. This does not work when I get there. "
Well, my guess is the embedded software engineer and the documentation writers were not on the same page.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
After looking at the wiring diagram I have some additional questions. The gas valve only has two wires coming out of it. "C" and "H". The "EXPLANATION" states "C" = ~ 24VAC and "H" = + 10VAC. I should expect two different values at each wire? This means my test in the image is not correct. Should I ground to the chassis aka the case of this heating unit and then test each wire separately? I work with DC not much with AC but I assume the same is needed which is a positive and negative source.
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so no issues during DHW, only in heating after an hour of run time, depending on your location and outdoor reset I would say we are running a low temp and small btu’s.
Just guessing, some dirty or cracked burners when running low fire isn’t quite hitting flame rod, Last time a 4 k hour service kit was done?
Have we removed the flame rod electrode / cleaned or just replaced?
Maybe just checking the Venturi for cracks or debris is the issue.
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It looks like a block diagram of the control board. I suspect the "H" +10 VDC is for another purpose other than the Gas Valve, probably the Max Thermostat function. There may be a 0 to 10 VDC analog input and the +10 VDC is a power source for it. I found no other relevant reference (other than this drawing) in the manual to the +10 VDC. The +10 VDC may be just an internal power source on the control board, kind of like the +5 VDC.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
"so no issues during DHW, only in heating after an hour of run time, depending on your location and outdoor reset I would say we are running a low temp and small btu’s." No issues during a DHW and only after 1 hour and 20 minutes it fault when trying to heat the the room with the thermostat request.
"Last time a 4 k hour service kit was done?" partial 1 month ago flush only and cleaning of the fan.
"Have we removed the flame rod electrode / cleaned or just replaced?" Have not removed at all.
"Maybe just checking the Venturi for cracks or debris is the issue." I can do this.
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Assuming this is what you are suggesting?
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Sounds like you have a problem when the unit goes on low fire this is why it works for DWH and for a while but once the boiler ramps down the flame has issues. On most boiler you can limit the max fire rate so it only runs on low. From there you can figure out where the issue is as it should fault out quickly, either gas or air side has problems.
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I like this approach very much. I am trying to construct a procedure to test things and not throw parts at it. Getting the ionization test correct would have helped narrow things down. That I still need to get back to. You mentioned "limit the max fire rate" that would be great to help diagnose so I do not have to wait over an hour for the fault to occur. No where in the documentation does it explain how to limit the max fire rate.
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Thanks
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parameter mode. Option 3.
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This from page 55?
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Ionization current test is fine. Had to do it my way which was make a DHW request from the shower at max hot. Then I measured the current and received the following values ranging between 6 - 8 which are greater than 4. From the documentation greater than 4 is ideal.
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The propane W.C. water column pressure at the machine if I have tested the correct port is fine at 10 “ W.C. There are two ports. I thought the top one labeled “Out” would be my test port. I opened it up and it did nothing. The port bellow I open and that bled propane.
The test was done under the same conditions a DHW request from the shower at max hot water temperature using a manometer.
Since the W.C. value is between 7 - 14 everything is fine. That is obviously if I am testing on the correct port.
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what does it drop to when it fires? That is the correct port
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unit goes out on low fire only, check for dirty/cracked burners, clean the flame rod, could be a Venturi/ gas valve issue
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If you are asking about the ionization current it drops to 6. Hilltown "…check for dirty/cracked burners, clean the flame rod…" when you say this you are talking about the burner cassette? The venturi I will double check that I cleaned it. The gas valve is what I initially checked for VAC in the original post? If yes would like to circle back and check that again if there is a better testing procedure. This was never completed and might be the issue "Replace the ignition assembly after every 4 year, whichever occurs first.".
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need to dig it to the flame rod/electrode and check the burner cassette
I finally found this document, I got it from Rinnai a few years back when I needed some assistance, passing it on.
Look in the tear down instructions and it talks about the burner and how to get to it., don’t turn the rods in the wrong direction.
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Thanks, thanks, thanks and more thanks!
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National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
The meter should be in the correct mode. It may not make a difference in this case, but you don't know unless it is in the correct mode. DC microAmps.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
to measure gas pressure pressure properly, do what you just did, then fire the boiler, record the value it drops to at ignition, run the boiler to high fire and record that value, then shut the boiler down and record that value. just having the correct static pressure is only part of it, you are looking to see what the total pressure drop is, if it drops an inch or more WC, you need to look at the gas supply, for pipe sizing 0.5" WC or less is what we design for, this is supposed to be under full load, so everything on the gas line running max (if your issue is intermittent it might be worth the check..) recording the value when you shut the unit down just makes sure the regulator doesn't sometimes lock up to high
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Interesting I need to measure DC not AC. I was not sure about this. How do you know this is VDC electrical system? [ Edit ] Asking because anything on the wiring diagrams always mention VAC. Thanks
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Absolutely understand this testing process. Will try again using these directives.
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They use Flame Rectification for the flame detection process. Rectification converts AC to DC. Often there is AC applied to the probe and the detection circuit detects the DC current through the flame. That is why the current is so low. If the detection circuit detects AC current flow it knows the the probe circuit is compromised to ground. And may shut the flame off during the trial period and even after.
Sadly I've seen some Fluke meters give almost the same reading when measuring DC milliVolts on either the AC or DC setting. Probably in that case since the DC was actually pulsating DC and not filtered DC or DC from a battery. Not sure if the behavior is the same measuring microAmps. So my conclusion is to double check the meter is in the correct mode.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System
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I really appreciate this answer. Will double check and test again.
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we run fine in DHW mode that is high fire so biggest demand, if it runs in this mode we can rule out gas pressure issues and wether or not the flame rod is reading flame and what is the ionization., I can only suggest to purchase the 4k hour service kit so you have the gaskets and open up the unit to inspect/clean inside the hex/burners. If that checks out replace the gas valve.
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Consider it done. Will order today and do that 4000 hours maintenance. Thanks again for the insights and guidance.
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Is this the correct service kit SKU:804000069?
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I completed the 4-year maintenance on this unit. However, the water heater continued to fault—this time much sooner and more frequently. Here's what occurred:
I attached a multimeter to check for DC voltage going to the gas shut-off valve. I observed 24 volts DC when the control board detected a domestic hot water request. The static propane pressure measured about 12.15 inches W.C. When the gas shut-off valve opened, the propane pressure dropped to 10.55 inches W.C., and the igniter began to burn.
I noticed that the gas shut-off valve would then close, causing the W.C. pressure to increase back to 12.15 inches, since it was no longer feeding propane to the igniter. After three hot water requests from the control board where the gas valve failed to open, the system triggered an E 02 fault.
Since I understand the theory of operation, have known-good values for comparison, and the proper testing tools and procedures, I have narrowed the issue down to either the gas valve or the control board.
There may be unknown unknowns, so I defer to your expertise. I am leaning toward the gas valve, but I’m not sure how to test the control board’s circuitry.
I also performed an ohm test on the gas valve, which measured 51.9 ohms.
Here is a video of the fault
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If the gas pressure drops, that means the gas valve opened. The issue is not likely to be the gas valve.
Maybe when you re-assembled, the ignitor or flame sensor moved and shorting to somewhere.
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