Hi. I have a new oil central heating system having had solid fuel previously. It’s stopped firing up and I’m not sure if it’s because the oil is low or if there’s a problem. Plumber not answering (I understand, it’s that time of year). He hasn’t been back to “flush/clean” the system. It was installed at the end of October this year. The cleaning fluids are here waiting but I wondered if that could have caused a problem. Absolutely fair enough if the oil is too low (I have attached a photo of the gauge). More oil coming on Tuesday. The radiators are the same ones that were in for seven years previously running from the solid fuel burner. Any advice would be greatly appreciated. Thank you