We have just purchased our first Hymer after many years with an Elddis. We are now trying to work out how everything works and how to fix all the faults "hidden" by the previous owner. Any hints and tips from Hymer owners would be most appreciated. The outside temp gauge reads -22 degrees but it is 10 degrees. Can we alter it? We also thought Hymers dumped their water when the temp was low - last night it was frosty in our driveway but the tank is still full of water? My husband just fixed the hot air system as it had been cut and we have now discovered a really narrow piece of ducting (brown with metal inside) near the water tank - what is that? Really would appreciated advice. Holmzie