Vitocal 300G pump not heating

[BogdanT]

Hello,

I have a Vitocal 300g installation for house heating, with a water reservoir buffer, and then connected to floor heating circuit. For the last 10 years it has worked without any issues, and without any changes in configuration or tinkering.

This winter, it doesn't seem the heating work anymore. The system does not show any error or message. The heating pump starts for 10-15 minutes and then stops for 5-6 hours. The temperature in the sensors seem correct (+/- 1 degree C) compared to external thermometer test.

I am attaching the display of the installation and the diagnostic screens. If anyone can help with any suggestions of how to debug this situation or what settings to change, I would be greatly appreciative.

I have reached out to the local Viessmann authorized partner and they didn't even bother coming on-site, just said the 300g system is not supported anymore and quoted me a new installation for 20.000 EUR saying that is the only solution.

Best regards,

Bogdan

[Flo_Schneider]

Hi Bogdan,

is the compressor shown as running in the system overview (second column from the left, at the bottom)? If so, and the compressor is not running, the problem lies with the compressor control. Either the control signal is not coming from the base circuit board, the EEV circuit board is not transmitting the control signal, or the compressor contactor is defective. In most cases, this indicates a defect in the EEV controller.

Best regards
Flo

[BogdanT]

Hello Flo,

Thank you for getting back to me. The "compressor icon" (second column from the left, at the bottom) shows as "running" / "moving", from what I can interpret the animation of a burning flame.

In this case, what could be the problem ?

Thank you,
Bogdan

[Küstenpumpe]

Wenn der Verdichter läuft und es liegen nur 7,4bara/12,4bara im Kältekreis  an, dann würde ich auf Gasmangel tippen.

Vorausgesetzt ich interpretiere die obigen Werte im Display richtig.

[BogdanT]

Hello,

Thank you for the input! Which "gas" are you referring to ? The unit is hooked up to electricity and the heat agent used for refrigeration/heating is a water/water underground pump. Am I missing something elementary ?
Please do excuse my questions, this is not my direct area of expertise, i am just a freezing customer 😞

[Küstenpumpe]

Your Heat Pump works like an Refrigerator......

With R410a

I think you  need a cryogenist to check it. 

[Flo_Schneider]

If the compressor symbol moves but the compressor itself is not running, the control signal to the compressor contactor must be checked. This is done from the base board via the EEV controller to the compressor contactor.

Best regards
Flo