On the last few days of our recent trip abroad, our Dometic 3 way fridge (c. 10 years old) started refusing to ignite when on gas, and has been struggling to maintain the right temperature in the fridge compartment with the thermostat set to the mid-point on the dial which is supposed to be the optimum. I've fitted a LCD temperature display and we rarely if ever see the air temperature go down to 5 degrees C or below. Oddly enough, if I blow hard through the bottom vent (near the burner) when the ignition is operating, the gas lights first time, but after a random length of time it fades and cuts out. I've tried igniting it with each of our cylinders (one is completely full) just to check the refillable wasn't getting low, and the problem is the same. The cooker and water heater are running fine as well. Is this likely to be something as simple as cack in the pipe or jet that needs poking out? I noticed the evaporation tray has a small amount of dark fluid in it, enough to cover the bottom. Is that normal?