DHW Sensor Error

gcdchico

We recently purchase a home that has a 20 year old Buderus system.

The Buderus Logmatic R 2107 displays DHW PROD Err. However we still have lots of hot water in the home. I have not yet tried to activate the floor radiant heating system. Does this error suggest the Buderus (80-100 Gal) holding tank has issues? Where would I search for the sensor?

Any suggestions please —- I live in Chico Ca with little to no radiant tech resources available.

hot_rod

Does the manual tell you what to check when you see that error code? Download a manual if there is not one on the site.

Usually it means a bad or disconnected or shorted sensor. You would need an ohm meter to check the esnsor when it 9s unhooked from the control

The manual would also show the ohm reading at various temperatures.

Alan (California Radiant) Forbes

It seems as though you have the error message without the symptom (no DHW). Here is the boiler manual with troubleshooting beginning on page 55. I received your voicemail and will call you back later today.

HVACNUT

In the meantime you can put the 2107 in manual mode ✋️ and turn the boiler temperature dial from auto to 140°. If the sensor is bad, the DHW temperature will be now 140°. Since you still have hot water, it might already be set up that way.

hot_rod

I have seen indirects that were not piped with check protection, or a failed check and the tank gets heated on any heat call to the boiler.