The
570 (and the
370, perhaps all their slide ins) is a partial by-pass machine (the heat exchanger) and that feature will dictate to some extent how you run it. On the far end of the spectrum you can't set yer wand down for 10 minutes (or more for that matter) and not have your water box temps possible rise to the design limit and then by-pass out the 165 degree thermo valve attached to the box. Those Cat thermo valves have a history of going out of spec; opening earlier. Hell yes install a new one to illuminate that possible weak link.
As mentioned above the vacuum driven actuator (Bimbo) needs to be moving freely. I check mine often as others do by peeking in and cycling the pump switch with the vacuum under a load. If the exhanger isn't bypassing hot air, the solution temp and the water box are in jeopardy and the water box temp valve is there to dump and will dump even faster if it's out of spec.
If the water box relief valve is within spec, the heat exchanger is cycling normal, you're limiting your time laying yer wand down and your tank is filling up, then as mentioned above turn the heat down. Start with Medium. The 570 has reputation in the field for being a "hot" machine. SS designed it for dual wanding. If you're single wanding at full throttle under full vacuum loads you should try managing the exchanger by asking it to by-pass at a lower temp then High.
Another thing to keep adjusted is your vac relief. SS has noted some high heat issues with the 570 and one thing they changed was setting the relief at 13" instead of the original 14". They actually made that a fleet wide spec to help hedge against issues on any models. The advertised spec on my
370 is 14" but the blower tag told the installer to deliver the machine at 13". If yer gonna single wand a 570 I'd limit yer vac to 13", limit yer idle time at the wand and turn temp to Med.
