Hi, I've recently moved house, initially I think the 2 rads were working, then nothing, I bled all rads and balanced them the best I could and they came in initially. Then stone cold... Plumber came fitted new trv's and return valves, heating worked, they left, then nothing from the 2 rads, they lifted floor boards said boiler was not in original place and said pipework needs changing!. Never came back! Now they are coming on, but not staying on? All other rads ok... any advice PLEASE. !