Carbon Monoxide Detected

Please can anyone help? We have just bought a secondhand caravan and have recently purchased a carbon monoxide alarm. This alarm was in the caravan for 2 weeks without going off but without electric or gas hook up, then we hooked up our caravan at home to electric to prepare for a trip away to get the fridge cold enough, gas still not connected, the only thing on was the fridge running on electric, after several hours of the fridge being on, the alarm went off. With the fridge turned off there is no carbon monoxide reading, but when on, the alarm continues to go off if left for several hours. I would appreciate it if anyone had a suggestion.
Many thanks,
Jacintha Feehan

I would strongly advise you to have your caravan looked at by the experts. You should book your caravan in for a full service at your nearest Caravan dealer. Explain to them what has happened and they should be able to rectify any problems. It should be money well spent and will also give you peace of mind, knowing that your caravan is in a safe condition.