Navien NPE 240A2 problems during and after installation

[DeagonTiger]

We installed our Navien NPE-240A2 last week in our attic. The plumber who installed it turned off the propane gas before he left and left the unit running. According to the use’s manual, it’s potentially harmful to the unit. As soon as we discovered that the unit was not operating properly (about three hour later) we called the plumbing company. By then the unit was warm to touch and the attic felt like it was 110 degrees (it was a 80-degree day). The second plumber turned the gas back on and it’s been running since. Yesterday we found out that the LCD screen was blank and no text was displayed. Another appointment is scheduled for tomorrow. We are concerned that the unit has suffered permanent damage during the installation and the lifespan and functionality is now compromised. Should we be concerned? What recourse do we have? If this unit is damaged, what parts need to be replaced to minimize future problems?

 

[Breplum]

the factory warranty covers LABOR for an entire year and materials for five.
Use NSS (navien service specialists from their website) for total coverage. But even non NSS but, listed plumbers (like me) on the website get reimbursed well now by Navien for the first year.
Really, the unit shuts itself off when it self checks are done every time it attempts to fire. After about three trys, it shuts down.
I doubt that the LCD screen went dead just from attempts to fire, but no matter. Also, if you call NSS plumber, they are required to have a big box of parts when they do the service, so any bad part can be readily replaced.
Of course your idiot plumbers should do everything at NO cost to you whatsoever.

 

[Sponsor]

 

[Fitter30]

What type of attic ventilation do have and color of the shingles?