Mastervolt Combi - fan cutting in frequently

[Ipapadi]

Boat based in the Med and just on-board 4 days after 6 month spell away. Mastervolt Combi 12v unit in place in Moody 425 since new 1999. Have just noticed tonight the fan cutting in frequently probably every 5 mins. There's only a fridge using power. Battery condition shows 14v, charging amps show 20. Solar panels keep batteries in good condition whilst away. As usual, with being away so long, the memory fades regarding usual sounds (couldn't be age!). I can recall it coming on more in the summer months but does anyone think this excessive or can anyone explain etc......Thanks

[captstu]

Do you leave your Combi turned off when away? If it is on, the fan will cycle.

[Ipapadi]

Stand down any replys - problem solved. By morning we solved it. There seremed to be a smell of gas, then checked the battery bank under centreline berth, starting battery boiling hence the smell;, hence the continous charging bringing on the fan!