I have had installed a new combi boiler ..room stat and radiator stats....when the heating comes on it makes a lot of banging noises .each time it fired up ..mainly in one room. ter came back and added mor lagging to pipework .and changed stat .anything else it could be?
Probably air trapped in the radiator or in the pipes. Find all the bleed valves, open them and let the air out. There's one bleed valve at the top of each radiator, and perhaps others in long pipe loops too. The air bubbles come because of dissolved air in the water which was used to fill the system. You ought to 'bleed' the system once a year at least.
Banging noise is usually an indication of air in the pipes. There should be bleeder valves on the radiators to let out air. A second possibility is that water pipes are not securely bolted down somewhere and the change in temperature is making the loose pipe vibrate.
You are not clear about the type of heating system you have: steam or hydronic. Steam system: One radiator is not level and the steam is making that banging when condensate water hits it. Radiators should be level or tilt a bit towards the supply pipe. Hydronic system: If water flow is not established in some of the smaller boilers the circulator will not turn on. The installer may have by-passed that circuit when wiring the boiler. The boiler actually steams and bucks until water flow is established. Trapped air does not make banging noises, it just blocks water flow and the radiator will not get hot. PEOPLE STOP GUESSING!!!!
