Navien 210a error code 048

[burtinos]

hello i have a navien 210a tankless model installed in a new house in the spring. I have received this error message three times in the last month, 048 . According to Navien tech support that error code is a gas pressure issue. MY contractor has been back and has checked the gas regulator and the gas switches on the unit itself. He says the pressure is set exactly where they recommend. Anyone esle have this issue any guidance will be greatly appreciated.

[jadnashua]

It is possible the pressure is dropping too low when multiple devices are on at the same time, say stove, WH, dryer, furnace. Since each comes on at random, it doesn't happen all of the time and a sample pressure check won't verify this. Could be the size of the supply line, the length and elbow count, the gas regulator, and probably other things.

[burtinos]

Thanks I have thought about this as a possibilty, i have a tankless boiler as well off the same feed from the regulator.

[AAnderson]

I'm out the door right now to tell the homeowners once again that the gas was never calculated correctly, the installer did a take off from the FAU on what was already a 3/4" X 65' line from the meter. they have had a repeated 03E error code and I've explained, the flame rectifier needs to see .5 VDC for 1.5 sec or the gas valve closes and will attempt this cycle 3 times before the error code comes on and you either have to trace the problem in this case to original installation or in the box and honestly I find the problems generally out side the heater. BTW, the original installed terminated the gas with a 3/4" copper water flex.
In my area of the central california coast, gas regulators in the marine influence that have been in service for decades, never had to open to deliver high demand and most I find are stuck partially closed from salt air. When found, these are replaced with new ones from the ultility. This same condition cause a growl in the first minute of ignition cycle and complaints are again aimed at the unit instead of the problem confusing the symptom with the tankless it's self.
If you are going to install a Navien as a professional, purchase and learn to use a dual port manometer to check low and high fire cycles before finishing the job not just take the heater out, install it and leave. If not, you leave service providers like me with more work than I need or want.

[D'Brie]

Is your gas meter properly sized? Possibly the gas company needs to come out and install a larger capacity meter?

[zl700]

D'Brie
its LP
Error code 48 is on LP units only and its a result of the gas burner wanting more capacity for a higher firing rate to meet flow/temp rise requirements and gas is not available.

Note: the yellow LED light on the circuit board will be flashing every 4 seconds confirming the desire for more BTU's/Gas that isnt there.