To start, has been a pleasure following the forums here for a few days now... With that said. One of my vans which I have owned a while now, (few years, Boxxer 421 with less than 1200 hours on a NEW Briggs Engine... Original one crapped out.) Unit has never been a primary clean unit for me. but other than constant, little issues and the need to replace engine it has run solid. 230-260 degree heat by end of pre-spray has never been an issue. Month ago I took it to Interlink to get a service done on the unit, the only real problem they saw was that the throttle and thus RPM were apparently too high. (Had run this RPM since new or at least unadjusted. Whether by coincidence, or something shortly after dropping the throttle I began having issues getting to full heat.. Diverter valve arm throttling, light engaging, etc, but very hard time getting up to temperature and remaining there. Was now taking 10 minutes or more to break the 200 degree mark, sometimes getting to 230 or so, but then randomly dropping down rapidly under normal cleaning use. (Same wand, same tips.) Even as much as to drop all temperature showing on gauge by completion of a 30 minute job. (Very random acting.) Then decide to take it to Jon Don, they do a full service, etc. I mention the throttle adjust which he inspects and claims is now a few hundred RPM below norm, and that this could be my issue... He adjusts the throttle back, runs the wand for a while and unit remains at heat. Of course assuming the unit is fixed I drive 2 hours home and prepare for my big night of cleaning under proper heat again....... Same issues as described.. Have noticed when we seem to be having the most heat issues, I am getting surplus steam blasting from exhaust which I have never noticed before......? Currently, Interlink nor Jon Don have any clue as to what the problem may be... Suggestions please? Before I drive it 2 hours in either direction to Jon Don or Interlink again.