Rinnai tankless gives error code 61 but works for a few hours after unplugging it

michaelbicycle

Our unit is 2 years old. We descaled it in May and the vinegar that came out was transparent turquoise color. It's worked perfectly until recently. We were away for 2 months and when we came back, it wouldn't work, it flashes Error Code 61. I removed the fan and cleaned it out several times but it wasn't really dirty and nothing major blocking it. It worked a few days then stopped again. After a tone of troubleshooting, I have realized that it works after turning it off and unplugging it for 10 seconds and then plugging it in. It makes some small grinding noises like it's cleaning or initializing or something. Then I turn it on and it works fine. After not being used for a few hours, it flashes error code 61 again. An electrician came and measured the amps on the fan and he thought it was working fine. And when it's working there is air coming out the outside vent so I don't think it's obstructed.

My guess, based on tons of googling, is that either the fan isn't spinning fast enough or the control board thinks the fan isn't spinning enough and it doesn't ignite. But I don't understand why it works fine after resetting it.

Every night I unplug it to reset it so we can take our showers. Is there anything I can do to troubleshoot this on my own? It's under warranty for parts so we'd need to pay for a service call and I guess another one if they have to change out a part. I asked a plumber I met in the neighborhood and he suggested calling an HVAC company because of the gas.

It's not urgent yet so I don't mind doing troubleshooting myself if there is anything I can try.

Thank you!

Teemok

Edit: Sorry I missed the obvious 2 years old part on my last post. Model and gas type? As you likely already know 61 is a fan related/air flow issue. Double check for proper venting: pipe size, length, number of bends, continuous pitch, clear termination. Clean intake screen? Is it possible something (sheet rock, masonry dust). has clogged the burner?

michaelbicycle

If there was a problem with the air flow, why would it work fine after resetting it? This is the part I can't figure out.

Teemok

If I knew the model….. On condensing models water can collect in poorly run flue pipes low spots and that results changes in air flow and intermittent codes. Some models have venturi flaps that fail. A given fan motor electrical input should result in a certain fan speed range. It may need to see an out of spec fault multiple times before it codes out. Your fan might be faulty in certain conditions.

I look at fault codes two ways: The control board is a lair or it's telling the truth. They tell the truth a lot more than not.

Teemok

Unplugging it just makes it try again and it then finds the same fault.

michaelbicycle

There is a big number by the barcode on the sticker on the inside: U356-0791 and U356-0749

Then on the schema diagram it says 2737,2432 model only and another line says 2737,2432,2730 so I guess it's one of these?

when you say "Unplugging it just makes it try again and it then finds the same fault.", I'm not sure I understand. Because after unplugging and resetting, it does work for 2-20 hours and then we get the same fault. So I think if there was really a problem it wouldn't work after resetting it. So there really isn't an issue, the control board thinks there is.

I'm not sure how a technician can diagnostic that. Rinnai said to have the technician call them, but I read some places charge a diagnostic fee for that sort of thing. Hence my desire to figure it out myself if I can.

Teemok

Diagnostic logic can seem strange. Bad logic can cost way more than paying for good logic. Sadly, paying someone called a technician is no guaranty you'll receive good logic but….. it is the most likely way to get it short of you having it yourself.

Accurately identifying the model you are dealing with is stage 1, full stop. Left outside panel is typical location.

Fuel type and pictures of the installation with an accurate vent piping description or diagram will invite more help than just me.

michaelbicycle

Hi, I didn't realize there is a sticker on the left side. I found the model number! RE180i.

I hope this gives you additional information, thank you for your help.

Teemok

OK, Natural gas, Re180i. If Rinnai would talk to you, they would ask for all these things first to insure that the install is correct before they start suspecting or testing for a bad parts.

How is this vented? The big pipe off the top. Pictures of the material? Total length estimate and a bend fitting count. Picture of termination to the outside?

There is an installation programing setting for flue length. It is setting (99) It's either A-long or B-short. It must match your installation.

The instruction manual has a how to on how to get into the settings menu.

Teemok

https://media.rinnai.us/salsify_asset/s-7e306b78-4033-45d2-af68-2d9a9f06d8e6/TB-185%20RE%20and%20REP%20Series%20Vent%20Length%20Parameter%20Setting.pdf

Teemok

There's this that may or may not apply to you:

https://media.rinnai.us/salsify_asset/s-e7dcfc55-9310-4a31-a87d-88ec34d44584/TB-190%20Non%20Condensing%20Termination%20Kit%20Update.pdf