Well I have done all the obvious things, new heat exchangers (Genuine), new heater cables fitted and adjusted, lagged all visible pipework and blocked rear vents / set centre one to shut (actually found cable under seat worked after liberal spraying with wd40 !) but still only getting a very small mount of "warm" air out of the front. I have belly pans fitted so cant see what's going on in the centre pipe but no rust at either end. So do I get the grinder out to remove the pan just for a look or is their anything else I can try ? I have a thirty HP style fan shroud with no thermostat at the moment but even on a 75 mile trip the air flow is next to nothing and tepid at best. I will fire up the compressor at the weekend and give the system a blow through but any other suggestions would be gratefully received :roll: