Sime super 90 – loud noise when calling DHW.
The problem with this boiler is when the Domestic Hot Water (DHW) thermostat is set to Max, and there is a demand for DHW the boiler fires up normal, the flame keeps increasing so does the temperature of the water until it reached to 60 C. At this point the boiler starts making a lot of noise and vibrates, like it is going to explode. I believed this is coming from the circulating pump. This is not happing when the DHW thermostat at minimum or half way through the scale i.e. when the water temperature is below 60 C. the Central heating working o.k. Any idea why the boiler is behaving like this?
Many thanks.
The problem with this boiler is when the Domestic Hot Water (DHW) thermostat is set to Max, and there is a demand for DHW the boiler fires up normal, the flame keeps increasing so does the temperature of the water until it reached to 60 C. At this point the boiler starts making a lot of noise and vibrates, like it is going to explode. I believed this is coming from the circulating pump. This is not happing when the DHW thermostat at minimum or half way through the scale i.e. when the water temperature is below 60 C. the Central heating working o.k. Any idea why the boiler is behaving like this?
Many thanks.