We had a Navien NPE-240S (nat gas) tankless water heater installed about one year ago and continue to smell unburned gas in our backyard coming from the exhaust vent of this unit. I would like to tell our story in hopes of getting some feedback from people experienced with tankless water heaters and possibly give a warning to people thinking of using a tankless water heater - specifically a Navien unit.
The long story...within weeks of the Navien install we smelled gas coming from the exhaust vent and error code E003. Roughly 1-2 per week we didn’t have hot water so I would look at the unit and see E003 error code. Resetting the unit would get the hot water working again. Told our general contractor and plumber who installed the unit about the problem and was told the unburned gas was coming from our main natural gas regulator on the side of the house. Clearly getting the run-around from these folks but was willing to undertake the journey to hopefully get things fixed. After more back and forth I called the natural gas utility to come check the gas smell. They used a gas detector to confirm it was coming from the tankless water heater and they also measured high CO from the exhaust.
From there our contractor and installer contacted Navien and the supplier to get support. It took a couple months and multiple tries but eventually Navien sent a “rep” to look at the unit. He was honest in admitting he was only a sales rep but he had some tools to do basic testing. He contacted NAvien phone support and the installer was there too. They did not have a combustion analyzer but through the Navien phone support they checked a few things and made some minor adjustments to the gas valve settings. I was skeptical but they thought there was a good chance this would fix the gas smell and the error code. When I asked more questions about the gas smell the Navien rep said a couple interesting things: I should try running the exhaust vent up the house to vent above the roof; and ff I wasn’t satisfied with the smell of unburned gas in our yard then maybe a tankless heater was not suitable for me.
The problems remained. Still smelling unburned gas and E003 error code. Another month or two of phone calls and Navien finally sent a real technician to troubleshoot. The fix for the E003 was painfully simple. The control unit was set for the wrong elevation. A few dip switch changes and this was fixed. The error code has not appeared since. The technician also attached the combustion analyzer and adjusted settings to be in the middle of CO and excess O2 acceptable ranges. So good news however the smell of unburned gas remains - I think it improved after the technician adjustments but the whole family can still smell gas about 30 ft away from the exhaust vent when the unit starts up.
At this point we are essentially giving up. Our contractor did an overall good job on our house reno. Customer support from Navien is horrible - they will give you the run around and suggest ridiculous fixes like venting through the roof.
So do we have a bum unit or is this typical for a tankless heater or specifically Navien heaters?
The long story...within weeks of the Navien install we smelled gas coming from the exhaust vent and error code E003. Roughly 1-2 per week we didn’t have hot water so I would look at the unit and see E003 error code. Resetting the unit would get the hot water working again. Told our general contractor and plumber who installed the unit about the problem and was told the unburned gas was coming from our main natural gas regulator on the side of the house. Clearly getting the run-around from these folks but was willing to undertake the journey to hopefully get things fixed. After more back and forth I called the natural gas utility to come check the gas smell. They used a gas detector to confirm it was coming from the tankless water heater and they also measured high CO from the exhaust.
From there our contractor and installer contacted Navien and the supplier to get support. It took a couple months and multiple tries but eventually Navien sent a “rep” to look at the unit. He was honest in admitting he was only a sales rep but he had some tools to do basic testing. He contacted NAvien phone support and the installer was there too. They did not have a combustion analyzer but through the Navien phone support they checked a few things and made some minor adjustments to the gas valve settings. I was skeptical but they thought there was a good chance this would fix the gas smell and the error code. When I asked more questions about the gas smell the Navien rep said a couple interesting things: I should try running the exhaust vent up the house to vent above the roof; and ff I wasn’t satisfied with the smell of unburned gas in our yard then maybe a tankless heater was not suitable for me.
The problems remained. Still smelling unburned gas and E003 error code. Another month or two of phone calls and Navien finally sent a real technician to troubleshoot. The fix for the E003 was painfully simple. The control unit was set for the wrong elevation. A few dip switch changes and this was fixed. The error code has not appeared since. The technician also attached the combustion analyzer and adjusted settings to be in the middle of CO and excess O2 acceptable ranges. So good news however the smell of unburned gas remains - I think it improved after the technician adjustments but the whole family can still smell gas about 30 ft away from the exhaust vent when the unit starts up.
At this point we are essentially giving up. Our contractor did an overall good job on our house reno. Customer support from Navien is horrible - they will give you the run around and suggest ridiculous fixes like venting through the roof.
So do we have a bum unit or is this typical for a tankless heater or specifically Navien heaters?
