what we should have bought and/or the way it should be built is a moot point...
therm valves are everywhere and they always have been...slide-ins....direct drives....PTO..we all have them...
and way back when...you did not hear too much about them..one every now and then would have a problem.....
I have had my thermal wave since 2010...she is cranking about 6000 hours now..I just replaced the therm valve for the very first time since I have had it about 2 or 3 weeks ago..but I also took the time and set it up to run in my climate.........I ran a
CDS unit for 5 years and never touched it once....
that being said....there is a bunch of different variables that people do not take into account...
slide-ins come a long way in the last 10 years or so...they are generating a lot more hot water than they ever use to...
ambient temperatures play a role in how much heat it will generate and how much the therm valve is going to dump...
how much air is circulating around a machine so it can breathe and allow heat to escape...
your water flow...
just to name a few that can affect the way your machine runs and how hot it may get to tell the therm valve to dump more often....
on my thermal wave...my climate is very hot with mild winters...being a liquid-cooled system...ambient temps play a big role on my machine...I can loose up to 20 degrees in our mild winters because of the cooler air that pulls into the system....and in our hot summers...I can peg the needle without even trying...so my therm valve is dumping way more in the summer than it is in the winter....If I ran a fresh tank and I wanted to divert the water...I would not have a choice but to have the external radiator with the fan set up to help me cool it the water that the therm valve is dumping to go into my fresh tank...and even then....110 to 115 outside temps.....I would still be pushing it...
My
570...totally different...much newer than my thermal wave...they took this machine and learned how to really harness the heat...controlling it is the bitch... you can not keep a therm valve in it...I finally just gave up on it...it is a must for me to run an A.P.O. with this machine so I just let it dump....in my temperatures...it can still push more heat then I want even though it is always dumping....so it is just not worth it to me to worry about...but for others... it has been a real pain...
Take these same machines...put them in a climate that is much cooler summers..and very cold winters..and it is an entirely different situation....
you can up your water flow to make your water move faster through the HX and not generate as much heat...
you notice that when you clean tile you are not pushing as much heat as when you are cleaning carpet...and if you have a lot of UPH..most have to go and dial back there machines or we will overheat because the water is hardly moving....
but not everyone can do this...the last thing you want to do is put down more than your equipment can recover...your just going to shoot yourself in the foot.....
they are what they are...and they are everywhere...they help release the heat out of a closed-looped system and help protect your equipment...it sucks that they have to dump into the waste tank and fill it faster then we want...but...99% of them have been like that forever...