wow, 3000 hours is impressive. Assume this is full time living and main source of heating?

Yes , it heats a room for my wife whom suffers from chronic arthritis and needs the temperature to be over 26 degrees! So it often runs for 24 hours a day I think that running at a high temperature also stops the carbon build up which we experienced with our Airtronic D2 unit which we had in our motor home. I had to regularly service these unit at 1000 to 1500 hours due to carbonisation and had to replace the flame screen. The fan motors had a fairly long life cycle ( D2) but very expensive to replace and not easy to repair ( had metal tags instead of screws to hold the units together). A total service kit with the gaskits and screens was a fairly expensive operation and for the price of one D2 full installation kit I can buy nearly six complete Chinese 8 Kw heaters. Which are very easy to service and the parts very cheap. Thanks for your reply