Rinnai - no hot water in frigid temps

[Ian W Walker]

I have a sneaky suspicion this wouldn't be the first post about this event. Purchased a Noritz t"h"ankless unit 2 years ago. Each year in the frigid months the unit stops producing HOT water, ONLY. I can get all the freezing cold water a man could want but when I turn the handle, at any water source in the house, to the right to get hot water - the water flow just STOPS. The fix last year was my technician coming back out, telling me that Rinnai put an update on their website that a long PVC extension pipe running outside along the wall of the house 12 inches off the ground was the fix. Unit is in my basement in Hanover, PA and right now we are in a deep freeze of about 4 degrees outside - coldest days of the year so far.

Anybody have same issues as described?
As a consumer, should I tell my technician to pull the unit and put a tank heater back in? If so, who should pay for this?

 

[Jadnashua]

Are there any error codes?

Are the exhaust and intake clear of snow and ice?

When they installed my mod-con boiler, they didn't follow the instructions for the termination, and on the first really cold day, the condensate froze over the intake and the thing shut down. They had to flip the intake and exhaust at the termination (per the pretty explicit instructions@!), and it works fine.