Cold weather is coming and we had some trouble with heating... It manifests during the night and as our bedroom is upstairs it did go unnoticed until we had to sleep in the spare room for a few days... This is the video from last winter. https://photos.app.goo.gl/dLBnLxFykMJ8o4M18 Note that during summer we had no problem while it was used to heat water. No noises or any signs of malfunctioning. It's enclosed in the kitchen cupboard with the only slight gap for ventilation... (so I plan to drill some more ventilation holes on the bottom for better air circulation) I can tell it was running very hot since it was installed (at one point fan seized and also had to replace the main wiring loom as all the connectors were blackened and brittle) Passed gas safety this summer. Any ideas?