My sister has just had her central heating boiler serviced and the gas engineer said that the gas pressure at the boiler is too low and could be caused by the pipe from the regulator having too many bends. Despite this, the boiler has been heating the house effectively.
Is low pressure at the boiler dangerous in any way?
He also said that the boiler was kettling. Is this always a symptom of poor water circulation and can airlocks cause the poor circulation?