Navien tankless

**xmdxtremek** · 02-24-2012, 09:36 AM

Hey guys we just recently moved into a newly renovated apartment. And it has a Navien NR180 unit. When the hot water is on it makes the most rediculous loud vibrations and grumbles you can hear it upstairs and all over the apartment and the damn thing is in my room when I am sleeping my roomies use hot water it is like hell. Is this normal for a unit to make loud grumbles? and this is not the the same engine noise that you hear spinning that is ok I can bear the engine cycle noise but this loud vibration noise is out of hand. Please tell me its not normal and can be fixed?

**ImpliedConsent** · 03-25-2012, 09:09 PM

Update from over the pond. We're well into our 2nd year of NR-210A ownership. I did an annual flush of the system before I deployed (NOV '11). My wife asked me about the servicing recently and said that she wanted to learn in case ... well ... you know. Since I clearly marked incoming/hot water, bought/cut the service lines/bucket, it was all there. I just pointed her to a YouTube video and she nailed it first time. I think she'll be OK. So far, we haven't had to call anyone concerning our hot water needs. I feel pretty comfortable with our experience. As I go back to wonder why my experience is different from others, I believe that it's still the quality of the installation, it's certainly not a DIY job. TY'all for my learning experience.

**jimdarcy** · 04-04-2012, 09:53 AM

Hi all, new user here, great forum. I am preparing to replace my 2, 18 year old 50G water heaters. I am on well water, one installer has recommended the Eternal Hybrid GU195, he says the stainless guts will hold up much better than copper. I currently have the traditional venting, access to uninterruptable power and an interior liquids drain. The question is...is Eternal with the premium price, and now it looks like the tax rebate is gone(not 100% sure on that). any thoughts or comments are appreciated.
Thanks
Jim

**QueBall** · 01-31-2013, 11:09 AM

I know. Responding to a 2008 thread.

Anyhow, Navien NR-210a installed here about 2 years ago. Been a pretty good experience I must say.

No, it's not maintenance free. You should flush / descale the unit on a regular basis. Frequency will depend on your local water quality. I probably only need to do it once a year here, but it's not very hard so I have done it more frequently than that.

Biggest problem I had was pretty silly. I was getting error code 10 indicating an air pressure sensor fault. The first time that happened I learned there was a screen on the incoming air vent that got plugged up with poplar (tree) fluff during the time of year when you would swear it's snowing outside there is so much of those seeds in the air. So no big deal, it's easy to scrape off. The next time it happened the filter was clean so I just reset the unit and it was fine again for a day. But it kept happening. So I went outside and found that the vent cover had fallen off. Apparently the BH rated vent pipe is a different material than the vent caps so the solvent didn't work to glue them together and the cap fell out of the exhaust vent. Well a mouse had taken the opportunity to start building a nest in a nice warm pipe. The mouse likely took off the first time we fired up the shower but now we had a pipe full of grass. Glad it wasn't the air intake that was missing the vent cap, at least the air flow was pushing the debris out rather than sucking it in. The exhaust pipe has a slope back to the heater so the condensate flows back instead of leaving icicles on the exhaust pipe so it was difficult to pull all the grass up and out, I'm sure there is a little bit left I couldn't reach with hooking up as many extensions to the shop vac pipe I could find.

So there is an installers note, do not assume the solvent you used for all the vent piping will work on that vent cap.

The A models have the recirculation pump and a mini buffer tank in them. I currently have mine set for internal recirculation using the mini tank. It's allows the heater to support low flow rates in my case. It doesn't really help with delivering hot water to the taps any faster since it still has to travel from the heater to the tap. I'm hoping to upgrade the piping to add recirculation to our sinks for hand washing. I can wait for the delivery of hot water for showers, but it would be nice to have the instant heat on our sinks for hand washing.

Installation on this was not easy. I did most of it myself with help from some handy family members. Our old builder grade tank died on us after a long life and we wanted it gone. Energy saving was not the primary goal, we wanted the space back and we wanted the endless hot water feature. There were rebates at the time to bring the cost down but it was certainly more expensive than simply replacing the old tank.
The obvious first challenge was venting. Difficult, but relatively straight forward. One reason for picking the Navien was so we could use the longer PVC pipes and place the heater on an inside wall. Plumber friend of mine told me to look into it.

The really hard bit that I was not expecting was upgrading the gas feed. I figured that all we needed to do was reroute the gas from the old heater to the new location but then I found out 1/2" gas line is not sufficient. Plan B was to come off the 3/4" line going to the furnace, BBQ, and garage heater but that was not enough to support all that stuff running on the same line at the same time.
So plan C. Run a brand new line all the way outside to the meter. What a chore, took me a few days, but it's perfect and with a home run to the meter we have never had a gas flow problem. I have read about many others who have flow or oscillation pressure problems with their gas and we have never once had issues with that. Inspection was impressed we caught this gas demand detail. I made one mistake I have been meaning to fix, I forgot to put a union after the shut off valve. It's only a problem if I need to remove the heater for some reason. It was -29*C the other day, would suck to have to wait for the furnace to turn off to get hot water. (That furnace is likely the next one to need replacing)

I see the latest model of Navien is designed to handle some of these retrofit challenges which makes for a pretty interesting product. If that was available back then we likely wouldn't have a problem pulling our gas connection off the line to the furnace but now that it's all done I'm glad we were able to do it the right way.

So what doesn't work as advertised? Well I had hoped the buffer thank would improve the time to get hot water from the tankless system but it doesn't seem to really work that well. It does help with low flow and the Navien seems pretty good at providing a more consistent temperature than another tankless install my parents had. There is still a noticeable delay to get hot water through the system. Going to investigate hooking up the recirculation system and running some return loops from the sinks to try and improve that. It seems like the internal buffer thank isn't large enough to work as I hoped. The vast majority of water volume of the tank ends up in the lines and although the design helps to reduce that water sandwich effect it's not gone as a little bit of warm water comes after a bit of time then it kind of stays luke warm like that until the actual hot water shows up. It does not drop down to really cold water like the unit I tried without a buffer but it doesn't give you the hot water as fast as you want. The internal buffer is an improvement but still not the solution to this complaint.

The noise is another potential issue. The exhaust fan motor and unit vibrates a bit. I am thinking of putting in some kind of gasket in between the unit and the wall to dampen the vibration. It's in the basement close to our garage entrance and not really any problem, if it were closer to bedrooms or active living spaces I might find it really annoying. If you are looking at these heaters then I suggest a very secure mounting point, and look into what can be done to isolate the vibration. It's not really loud but the vibration kind of reverberates through the wall.

The maintenance isn't any worse than draining a regular tank would be. Anyone who thought it was maintenance free is nuts. But if you do a good job installing it things work really well.

**calabasasplumbing1234** · 02-11-2013, 11:00 AM

I second that. The Navian tankless water heater system has been what I have found to be the best system to recommend. They rarely have any problems, and are built well.

**QueBall** · 02-11-2013, 12:49 PM

Had a small problem over the weekend with my NR-210A but it was relatively easy to fix.

There is some kind of air purge valve on the top of the recirculation pump. Mine was leaking and water was dripping out of the threads on the cap (kind of a plastic thumbscrew thing sealing the hole that lets air out of the top of the pump)

I'm not really sure how this valve is supposed to function as I could find no documentation about it in the Navien service manual. It isn't even listed as a separate replacement part, it's just that black plastic thing that sticks up from the top of the recirculation pump. Would hate to have to buy an entire new pump if this was the only part that needed replacement as it is really easy to remove.

Once I took mine off I found the threads of the small purge valve were crusty with mineral build up. A quick soak in a vinegar bath and I was able to remove the crust. Put it back on top of the pump and no more leak.

This happened right after I had shut the water off and drained the tank. When I turned the water back on I had turned it on very slowly at very low pressure. I suspect there was not enough pressure to push against the valve to keep it shut or the part of the valve that floats went a bit askew and did not make a good seal. It seems like it's designed to allow air to pass and then when the full water pressure hits it the pressure is supposed to close the valve but I think I screwed that up by applying low water pressure. (I was doing some other plumbing in the house and one of the old shut off valves on a toilet was leaking so I wanted low pressure in the lines to test with.)

So whatever that thing is on the top of the recirculation pump may need periodic cleaning when you are doing the regular maintenance / flushing of the tank. Going to add it to my list of things to do. It's a bit of a pain to remove without also removing the motherboard but I have small enough hands I was able to do it without removing anything else. You may have to look at the service manual for removing the recirculation pump to see what connections you can remove to get back there if you don't have freakishly small hands like me.

**Cafen8ed** · 02-19-2013, 07:03 AM

I had a Navien CH-240 installed last Feb. A few weeks ago it stopped making the rumbling noise. I noticed the temp on the thermostat does not reach the 185 as it had in the past. It stays 10-20 degrees lower. If I lower the temp to 160 it still stays 10 degrees lower. (then when the heat comes on , it is coolish air coming hot- we always have hot water)
When using hot water it drops 60 degrees and does not heat up quickly like it had. Installer told me it was cold outside so water, propane takes time to heat. I called a Navien recommended repair and now they have said the unit is too small to provide service for 3 furnaces and the hot water. Another repairman came out prior, said the flame was not staying constant (there are no error codes) but he was only familiar with the tankless that are used for hot water not dual - furnace & hot water. They are coming back today but hinted that there were other issues with furnace and piping. That did not answer my question about why the unit was noisy and reaching temperatures. They were proposing another type of unit- Pioneer boiler. Any suggestions? Furnaces were installed at the same time- so everything is about 11 months old.

**Swedefj40** · 03-28-2013, 03:41 PM

Hi, I've been having the E010 error code on my Navien 210 model pretty much since it was installed 5 years ago. Normally I would clean out the air inlet strainer and all would be good. This would happen every 6 months or so so I didn't think nothing of it. However, I am now getting the error every few days now even though the filter is clean. I also noticed that there is a lot of suction as I pull off the front cover of the unit. If I leave the cover off the unit, the error code does not come on nearly as often either. Navien has not responded to my e-mails either. Anyone have any suggestions?

**jadnashua** · 03-28-2013, 05:50 PM

It sounds like the air inlet pipe is clogged...you may need to go all the way outside and take a look. The unit should get all of its combustion air from outside, which means there should not be a vacuum in the cabinet.