Gary Charters 0 Posted December 1, 2016 I have no reposonse from the heater, so no demister or anything. I thought if I buy and replace a XD~XF Heater Control Valve / Tap, this may help. Has anyone came accross this problem? Cheers. Share this post Link to post Share on other sites
hendrixhc 10,921 Posted December 1, 2016 I d be visually checking the vacuum line is actually opening the tap. Also check the tap hasnt seized. Share this post Link to post Share on other sites
bear351c 10,273 Posted December 2, 2016 Yep, like James suggested, the heater tap corrodes with anything but nice water.... . Share this post Link to post Share on other sites