Michael, thanks for your response. It's an electric model circa 2003/5. Old I know but they are pretty basic and it functions well in all respects, other than the heating at the moment. Don't like throwing things away!
Michael, I checked this when we first had the problem. With the hose connected the flow seems pretty much OK though I am not sure exactly what to expect. Certainly the hose was kicking around a bit and lint was flying everywhere. Have removed as much lint as poss. from hose and ports on machine. Air temp at exit is warm, not hot. My wife tells me glass is normally hot to touch. Not the case now. As I said have changed heater and stat but no improvement.
Michael, dryer out and top removed. Wiring looks fine no signs of scorching or cracking anywhere. Have given the connectors a good "jiggle" just for luck and run the machine at high heat set for 30 mins. The machine case behind the heater is too hot to touch for more than a second and exit temp from hose is 51 deg., plus glass is much hotter than previous. Maybe we have a dreaded intermittent fault in the coil relay. Guess we just have to keep an eye on it. Sounds like a board replacement could be uneconomic so fingers crossed.
Many thanks for all your help. Would appreciate your comment on exit temp. Thanks again.
Michael, sorry no access to computer last few days. So far so good but will anticipate feedback from main user [wife] should things deteriorate again. If it does will consider main board though a replacement may be more economic. Thanks for all your help. Have rated you previously and haven't seen rating option since. Hopefully that one rating was sufficient.