# Navien CR-240a tankless water heater issues



## PoWn3d_0704 (Jan 10, 2010)

Hello, we just installed a Navien CC-240a gas tankless hot water heater in our garage. However, there seems to be a major problem with it. With everything hooked up (correctly I might add) there is no response from the water heater after being plugged in. On the control board, the display does not turn on, there is no clicking from the ignitor, and no pump trys to run. The only thing that changes is the red LED light on the
middle of the board. This light stays on for about 15 seconds, turns off for about 15 seconds, and then blinks 36 times. That's it, there is no other response from the unit. After researching it online, I have yet to run across another person who has had this problem. We checked the flow sensor, made sure the plug polerities are correct, there is plenty of water running to the unit as well. I don't know what else to check. 

I found a website that told us to hold the left button on the control board down until the display read 0.0 (to check the flow sensor), but that never happens. It just sits there, blinking at us in a very mocking way. 

If anyone has any kind of idea as to get the dang thing up and running, or at least responding, please let me know here or at my email, which is my username, but @yahoo.com

thank you sooooo much (in advance)


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## jklump (Jan 10, 2010)

I am not sure if you got a response but hopefully you were able to get it running. I have a Navien CR 210A and it has been a real headache. The wter turns cold randomly duirng a shower and now there is somethign wrong with the gas valve (I think). Does anyone have any experinece with either of these issues?

Any help woudl be greatly appreciated.


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## crmont (Jan 10, 2010)

PoWn3d_0704 said:


> Hello, we just installed a Navien CC-240a gas tankless hot water heater in our garage. However, there seems to be a major problem with it. With everything hooked up (correctly I might add) there is no response from the water heater after being plugged in. On the control board, the display does not turn on, there is no clicking from the ignitor, and no pump trys to run. The only thing that changes is the red LED light on the
> middle of the board. This light stays on for about 15 seconds, turns off for about 15 seconds, and then blinks 36 times. That's it, there is no other response from the unit. After researching it online, I have yet to run across another person who has had this problem. We checked the flow sensor, made sure the plug polerities are correct, there is plenty of water running to the unit as well. I don't know what else to check.
> 
> I found a website that told us to hold the left button on the control board down until the display read 0.0 (to check the flow sensor), but that never happens. It just sits there, blinking at us in a very mocking way.
> ...


You are kidding! I'm having EXACTLY the same issue. The system is a dead dog and what's really annoying is that the website doesn't describe a NORMAL sequence of operation (like does the LED display light up normally?) Anyway I'm a very experienced HVAC tech and I can't figure it out. I think the board is bad. The only thing I've found that is strange is the 110 volt power cord supplied with the unit is backwards so 110v power is supplied on the neutral leg of the GFI power switch. However the manual doesn't reference polarity as an issue but it does talk about proper grounding. I have made sure the transformer is working and the board has power. I've got 30 hours in the sucker. Please keep me posted.


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## jklump (Jan 10, 2010)

My plumber came today and brought the local sales rep for Navien. They replaced the mother board and so far so good. If you can, call the local rep. He cam with teh new board and installed it, I think they were here a couple hours and no charge.

Thanks for your response. Good luck.


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## hpressman (Feb 12, 2010)

*180-a*

Hey, what website were you on where it gave you troubleshooting? I just had an NR-180A installed and have even had the tech come back. It takes about 3-4 minutes for the water to get hot and when I have more than one faucet on, the flow out gets reduced to a trickle. The tech tells me it is because the input water temp is so cold (in southeastern PA), but I don't think the internal recirculation is turned on. How do you guys have this set up in yours?


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## kermit2010 (Nov 24, 2010)

*Same issue here*



jklump said:


> I am not sure if you got a response but hopefully you were able to get it running. I have a Navien CR 210A and it has been a real headache. The wter turns cold randomly duirng a shower and now there is somethign wrong with the gas valve (I think). Does anyone have any experinece with either of these issues?
> 
> Any help woudl be greatly appreciated.


I have the same problem, only we have a 240A. You keep having to play with the faucets to keep the temperature steady. I also get E010 in cold temps. Happened again last night, we had no hot water until this morning, when it started to work again. Will be talking to the plumbing outfit that installed it today. Anyone have any thoughts on the E010 issue?


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## hpressman (Feb 12, 2010)

We had that problem with pur 240a unit. I think it was the same code. There is a black vinyl tube inside the unit that wasn't fully connected. The tech moved it and it started working. It is about a quarter inch in diameter and was black in my unit. Just make sure the connections are tight.


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## Navien Plumber (Jan 19, 2011)

I have 40 (+) Navien units out there. This is a strange one, does the electrical plug outlet have a GFI button. I have found this is sometimes an issue. Do you have the wall mounted lcd control?


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## yeagerbomber (Mar 9, 2011)

*Navian issues*

Well, I have serviced about 40 of the Navian Tankless heaters this year. I find that the most common problem when homeowners install them is not having the correct gas sizing to the unit and not enough water pressure to the house. Even though there may be 3/4" stubbing out of the wall may not always be alright. You need to check gas sizing from the distance from the meter to were your unit is located. Most of the time we have to do some sort of gas repipe to accomidate the BTU's. Also, the venting is important as well. Make sure you have a condensate drain on your system if the venting exceeds 5' vertical feet. This is always the problem why the boards short out or other electrical issues occur. And last the factory sends them with a default dip switch setting on the board for the circ pump, make sure you set it to your application. Hope this info helps :thumbup:


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## metalman1 (Apr 2, 2011)

*navien CC240A*

Had this unit installed about a year and a half ago, it was used for an addition to our house only, with infloor heating, when our water heater went in the main house we opened the valves and started using the Navien which has cold and hot fluctuations, parts but no labour warranty, not nice, Navien sent new sensors, board and hoses(which plumber put hoses in wrong spot and took tech poeple to figure it for him 2.5 hours out of my pocket)maybe someone out there can help, after new parts same problem, but did figure one thing out, I have the shower unit with one fixed head and one wand, total of 5 GPM with both on water is hot, shut one off water turns cold, answers? anybody please.


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## Manufact. Rep (Apr 27, 2011)

*Metalman*

Check and see if the water coming out of faucets is steady hot. If so the problem is with the Shower valve. Water heaters heat water and I get lots of calls about showers going cold and temps fluctuating and when we turn on 4 of 5 faucets we get consistant water temps but the shower valves are pressure balanced and/or Thermostaticly controled. cold water overcomes the pressure of the hot water and the showewr valve operates incorrectly.


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## metalman1 (Apr 2, 2011)

So what your saying is, if I replace my old tank water heater it will fix this problem since it worked fine before, two showers in house both doing same thing, filled hot tub on weekend, turned tap to full hot then took six hours for tub to bring temperature from 85 degrees. I just love this machine!


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## Thaddus (Oct 23, 2011)

*CR-240A off gassing natural gas*

I have had a CR-240A for almost three years. All of the warrenty work has been preformed by the plumbers that installed the unit. Last night I had a visit from the police, fire department and the local gas utility company because my neighbor was smelling natural gas outside his and my house. After a lot of checking we tracked the smell to the exhurst port of my Navien cr-240a tankless water heater. When the exhust gasses were measured there was over 125ppm of unburned natural gas being exhausted from the unit. According to the local gas utility worker an acceptable reading is typically under 10 ppm of conbustable gas in the exhaust. He caution tagged my water heater and shut it down. The plumber came out checked over the unit, called tech support and was told that 125ppm was normal. If that is normal then why did the utility shut it down and why do I smell natural gas if it is running. Has anyone else had this problem? It does not sound 98% effecient to me.


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## vcheez (Jul 12, 2010)

Thaddus said:


> I have had a CR-240A for almost three years. All of the warrenty work has been preformed by the plumbers that installed the unit. Last night I had a visit from the police, fire department and the local gas utility company because my neighbor was smelling natural gas outside his and my house. After a lot of checking we tracked the smell to the exhurst port of my Navien cr-240a tankless water heater. When the exhust gasses were measured there was over 125ppm of unburned natural gas being exhausted from the unit. According to the local gas utility worker an acceptable reading is typically under 10 ppm of conbustable gas in the exhaust. He caution tagged my water heater and shut it down. The plumber came out checked over the unit, called tech support and was told that 125ppm was normal. If that is normal then why did the utility shut it down and why do I smell natural gas if it is running. Has anyone else had this problem? It does not sound 98% effecient to me.


I'm not a plumber but I sell, install and service flammable gas monitors and will say that 125ppm is not even close to being a flammable or explosive concentration of natural gas. The lower explosion limit for methane, the main component of natural gas is around 50,000ppm. Natural gas is odorized with stinky sulfur based mercaptan compounds that can be sniffed by the human nose at concentrations in the low ppb range. 
Even though 125ppm is not flammable, the smell of mercaptans in natural gas is annoying and freaks out most people including me. I wish I had an answer about why the utility shut you down but it sounds like they based their decision on the local utility worker stating that 10ppm or less is normal. 
I'm sorry to hear about your problems but I'm glad that you've shared it here at the forum. My engineer buddy did his research and he said that in his opinion, the Navian tankless water heaters are the best. He hasn't made his purchase yet so I will make sure to share your post with him. 

Good Luck,
VC


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## JJP301 (Apr 25, 2012)

I find this interesting. Everyone I talk to say this is the best tankless water heater on the market.

With all these problems did anyone check the gas pressure at the water heater.

The pipe should be sized according to distance and load.
If you use the same pipe size as the old tank water heater and the tankless heater has more BTU's , which it probably does, you may not
have enough pressure to operate the heater. If it is border line and other gas appliances come on it may cause the fluctuation in the amount of gas available causing temp problem everyone is complaining about.

Before the heater regulator valve you should have a minimum of 5.5 WC
and after the regulator you have a minimum of 3.5 WC


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## martoranas (May 10, 2012)

*Navien CR-240 water heater issues*

Navien corp. of America (made in South Korea) sells a product that is a work in progress. Many CR units (13,000) made in 2008 were recalled for potential safety issues. They were also equipped with faulty PCB's. Numerous other problems forced the company to discontinue the CR line and replace it with the NR model. If you own a CR model and are having on-going problems, I recommend contacting your installer and have them explain your misfortunes to Naviens' service tech. I have been able to upgrade two customers to NR models so far, no questions asked. 
I cannot stress the importance of proper gas supply pressure. In our area most gas meters are capable of supplying about 250,000 btu's. An NR-240A model will consume 200,000 btu's itself. That leaves little room for your 90,000 btu gas furnace, 40,000 btu gas range, 30,000 btu gas dryer, 40,000 btu gas logset and so on. Your tankless water heater will be the largest appliance (btu's) in your home by far. If your meter is undersized or supply runs too long or undersized it will be the Navien that will suffer. Did your installer check gas inlet pressure at the Navien with all other gas appliances turned on? Do not assume because it worked at one time that gas pressure cannot be the problem. Regulators fail, peoples usage habits change and quality and pressure of suppliers gas fluctuate. Don't be so quick to blame the appliance.
In my opinion, the jury is still out on this product but I am glad to see that the company recognizes some of it's problems and is addressing them.


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## JJP301 (Apr 25, 2012)

The supplier I use said he hasn't seen any problems from the units they sold. He is their technical rep so he would get the calls


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## VIPlumber (Aug 2, 2010)

martoranas said:


> Navien corp. of America (made in South Korea) sells a product that is a work in progress. Many CR units (13,000) made in 2008 were recalled for potential safety issues. They were also equipped with faulty PCB's. Numerous other problems forced the company to discontinue the CR line and replace it with the NR model. If you own a CR model and are having on-going problems, I recommend contacting your installer and have them explain your misfortunes to Naviens' service tech. I have been able to upgrade two customers to NR models so far, no questions asked.
> I cannot stress the importance of *proper gas supply pressure*. In our area most gas meters are capable of supplying about 250,000 btu's. An NR-240A model will consume 200,000 btu's itself. That leaves little room for your 90,000 btu gas furnace, 40,000 btu gas range, 30,000 btu gas dryer, 40,000 btu gas logset and so on. Your tankless water heater will be the largest appliance (btu's) in your home by far. If your *meter is undersized* or *supply runs too long* or *undersized* it will be the Navien that will suffer. Did your installer check *gas inlet pressure* at the Navien with all other gas appliances turned on? Do not assume because it worked at one time that gas pressure cannot be the problem. Regulators fail, peoples usage habits change and quality and pressure of suppliers gas fluctuate. Don't be so quick to blame the appliance.
> In my opinion, the jury is still out on this product but I am glad to see that the company recognizes some of it's problems and is addressing them.


That's the biggest load of hogwash I've read in a while. All the items I highlighted are the responsibility of the certified/ticketed gas installer and not the manufacturer. If you've upgraded some of your clients' units based on the highlighted items above, maybe it's time you went and got your gas ticket or took a refresher course. I've installed maybe only 20 or so but I've not had one issue, except for the gas reg at my house which failed. And that is not made or supplied by Navien.

Done right this is a pretty good product. Done wrong, well all you have to do is Google "Navien problem(s)" or something similar.


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## martoranas (May 10, 2012)

I was responding in general to problems with Navien units. The two I replaced under warranty had leaking heat exchangers. Do not downplay gas supply issues, regardless of who is at fault. The most recent Navien training class we attended had an instructor who went on and on about gas supply issues. If you have a problem with what I posted then you are in conflict with him , not me.


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## tleco (Jul 30, 2009)

2 years ago I bought a Navien Tankless. The first unit worked for 1 day then it is running hot and cold. After some research I came to realized that it is the water FLOW Sensor. I went to the supplier and get another flow sensor. it worked for 2 days and the same problem came up. The CS told me that they are having so many problems with Navien and Suggested another brand.
I went with Noritz.
Technically - on Paper Navien is a great Tankless. The problem is that $25 sensor error ruined the machine


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