Thursday, September 12, 2013

Studying the Navien Problem

As indicated in an earlier blog post, we have had problems with our Navien NR-180A-NG tankless hot water system each winter since its installation. The system fails to ignite (Error Code E003), and thus won't deliver hot water. This happens only during winter weather, i.e., when it's very cold outside. The last time it happened was in January 2013. The error code displayed then was E027, "Abnormal activity of the air pressure sensor."

One of the theories for why we're experiencing this problem is buildup of condensate in the flue that exhausts hot air from the Navien. The flue piping has a long level section that elbows up (see photo) and water could collect here in the winter, since outside air will be cold and make the pipe cold. If enough water is collecting there, it may be blocking exhaust enough so that the system senses an air pressure problem. We've been able to reboot (unplug and plug) the system and get it working again.
Matt and Chris Q of Campbell & Company were out today to examine the system and discuss what might be done to correct the problem. It was generally agreed that the long run of the vent pipe and failure to slope the pipe the designated amount (1/4" per foot) is the major contributing factor in the system failures during cold weather. However, Matt hypothesized that another factor may be the fact that the cold air in the winter is harder to move through the long exhaust pipe. The combination of the condensate building up in the pipe and the added difficulty of moving the heavier cold air may be causing the air pressure anomaly and failure to ignite.

We hesitate to go in and realign the exhaust pipe because it is housed in a chase for cosmetic reasons (see photo below).


Matt disconnected the intake pipe on the Navien so that warm air is being drawn from inside the home (see photo below), rather than outside. We'll see if this fixes the problem when the weather turns cold. If not, we'll have to cut a hole in the chase where the vent pipe is located and attempt to incline the pipe and exhaust it directly under the deck instead of on the roof.


Sunday, June 2, 2013

Update: 3302 W 42nd, June 2013





Installation of a nuvoH2O Water Treatment System

We've been in our new home a little over 2 years and decided it's time to do something about the hard water. I'm not sure what the hardness level is, but we've been getting buildup in the dishwasher, and on shower doors.

We had a water "softener" in our previous home and had it removed after a few years because of continued reliability problems, plus we were never happy with using salt to soften our water. We had the new home plumbed for a water softener, but hadn't decided yet what we wanted to use for water treatment.

After doing some research, I decided to install a system that uses chelation to remove the hardening agents. The system we chose was the nuvoH2O.

According to the nuvoH2O web site;
"The nuvoH2O Manor system uses revolutionary technology to lower the PH level of water based on the basic scientific process of chelation in which the metal ions causing hard water, principally calcium and magnesium, are bound to the chelating agent in nuvoH2O's FDA-approved, proprietary formulation, which keeps the minerals soluble and unable to cause hard water problems. The resulting water is soft and healthy for all of your household uses, including drinking, bathing, washing, and lawn and plant watering."

Although the web site advises that the system can be self-installed, I decided to hire my plumber to handle it. I'm glad I did. Their special tools and expertise made it an easier job than it would've been for me.

nuvoH2O system was placed next to the Navien tankless hotwater heater

PEX pipe was used for piping and a ProPEX Expander tool was useful in the installation
video
Completed installation
After we've used the nuvoH2O system a couple of months, I'll blog about what I think of it. I'll also show how the canister filter is removed and replaced.

Wednesday, January 2, 2013

Navien Water Heater Problems

We are having intermittent problems with our tankless water heater. The system is a Navien NR-180A-NG (operates on natural gas). It was installed in December 2010. The system sometimes fails to deliver hot water. Water will flow, but it's cold. This problem only occurs in the winter.

Examination of the control panel indicates the system is in error mode (red light flashing). I didn't note the error code (will do that next time). The system can be restarted by unplugging it and plugging it back in. This morning it took several tries and about 15 minutes to get the system working.

The service tech examined the system and ran some tests, but when he arrived the system was working and he couldn't duplicate the malfunction. He did set an internal recirculation system (we did not get the external recirculation) so the system is supposed to circulate hot water internally from 0600 to 0900 and from 1800 to 2100. This might improve the time it takes to get hot water to various locations in the house, but it's hard to see how it will help the intermittent problem.

One of the theories for why we're having a problem is buildup of condensate in the flue that exhausts hot air from the Navien. The flue piping has a level section that elbows up (see photo) and water could collect here in the winter, since outside air will be cold and make the pipe cold. If enough water is collecting there, it may be blocking exhaust enough so that the system overheats. We'll have to see what the error code tells us next time the system fails.

Vent flue (horizontal) and air intake for tankless water heater.
Flue enters inside wall of garage and goes straight up to roof.
This piping is now contained in a chase.