Primula, Margherita, Orchidea, Gardenia stoves - noise and vibration

There have been several reports of Primula stoves exibiting excessive noise and vibration when operating at maximum power leveles and/or maximum smoke fan speeds. Initial investigation when these symptoms are presented should focus on the smoke fan to ensure that it is properly secured to its housing, that it is spinning true and in balance. Secondly, that other associated structures, side panels and pipework are properly attached and not loose.

If no problem is found with these components, the problem may be due to the combustion air inlet tube. The tube that is used on this range of Red 365 stoves is the same component as is used on the MCZ Active Air range of stove (e.g. Musa Ego, Suite, etc). In the MCZ range of stoves, an air flow sensor fits into a slot in this tube. The Red 365 range of stoves does not use an airflow sensor (it uses an air pressure switch, same as the Compact boilers), but the slot remains in the tube and is unused and uncovered. As a result, at certain smoke fan speeds and hence certain airflow speeds within this tube, a resonant frequency is met which induces a severe vibration in the boiler structure. The recommended way to resolve this issue at present is to seal the slot in this tube with aluminium tape, or alternatively, a redundant airflow sensor can be fitted to fill the slot.