Hi.
I am struggling with a new Noritz CB 180 installation.
We have a brand new install - less than a month old. Its a CB 180 in a condo serving both domestic hot water and a First Co Airhandler Hot Water Coil.
The system worked great for the first week. After that, the client called complaining that it shut down on Error 54 (low water pressure/ system pressure 4PSI below heating loop set point) every morning. They would reset the unit and it would run fine until the following morning. This unfortunately started happening more frequently - several times a day.
What we figured out was that the system pressure was plummeting when the domestic side was in use. We installed a set up that allowed us to manually fill and monitor system pressure both at the unit and in the loop at the same time. System pressure during heating loop use is all over the map. It goes as low as 16, spikes as high as 37, T&P does not trigger. We manually fill, heating loop gauge goes up to 15 PSI, unit works, we tap domestic water, heating loop pressure gauge that we installed simply drops to zero, units digital read-out is all over the place, system codes out of 54.
My suspicion is a bad pressure sensor or three-way mix inside the unit but any insight is greatly appreciated.
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