I have a Buderus Logamax Plus GB142-24 that will not produce heat. I first noticed this morning, but it's probably been like this for a day or two. Initial observation is that a few rooms in the house seemed a bit cold (we have radiant heating).
I'm comfortable with DIY stuff, but I would normally call a service tech since this is a gas appliance – happy to trade dollars when there's risk involved. Of course, everything is different with covid in the mix. I would like to eliminate any obvious and/or easy fixes myself before calling someone, so I would appreciate any suggestions / next steps.
Things I've done / tried:
- turn it off/on – no change at startup, went straight to ~82F and didn't light the pilot, no error codes
- empty out condensate trap – last emptied ~11 months ago, had some accumulation this time but didn't seem excessive
- adjusted temperature for DHW – turned down to "Eco" (lowest setting between "0" and "90") from starting position of ~120F. Within a few seconds of doing this, the boiler fired up, lit the pilot, and temperature on console showed 120F and climbing. It turned out this was temporary – I walked away, and returned 10 minutes later find the boiler again sitting idle, temperature display showing ~80F like before.
- adjusted temperature for heater water – tried various values, no observeable change
- check diagnostics – console shows "0Y" which the manual says "flow temperature higher than set" without further detail. No error codes. This shows that the boiler thinks things are fine, normal operation, no issues.
- called Bosch support – they wouldn't tell me anything without a licensed tech standing next to me, even though I explained that's the very point I'm trying to avoid.
- verified that inlet and outlet are both clear, unobstructed at the exterior of the home
0Y – The actual flow temperature is higher than the set temperature. The boiler switches off.
0Y – The temperature at the flow sensor is more than 95 ° C.
This message may appear in the absence of a malfunction if all valves on the radiators are suddenly closed or after the hot water is removed from the GB072-24K.
Check the working pressure in the heating system. Open the service valves.
the heating circuit pump Electrical connection to the main controller BC20.
Rotate or replace the heating circuit pump.
Correctly set the power of the pump or its characteristic and reconcile with maximum power.
Check for damaged or short circuit to the flow temp. sensor, replace if necessary.
0Y – High temperature on the hot water temperature sensor
Check the correct position of the sensor.
Check it, and if it is defective, replace
Insert the KIM correctly, replace if necessary.
EDIT: added another thing that I checked earlier, but hadn't included in the list: verified that inlet and outlet are both clear, unobstructed at the exterior of the home)