
Originally Posted by
John Bostwick
I too have a UDS and the way I run my HM setup Fan, no more then 30% and I have a 3/4 ball valve at about half open or less. The way I tuned my UDS was to set it up without the HM and then get it up to temp. Once at temp and stable start closing the ball valve until the temp. starts dropping and put a mark on the valve at that point. Now when you put the HM on the UDS, it will raise the temp to set point and fairly stable.
You may also want to up the fan speed more then the 30%, I have mine because I use a big 32cfm blower. The way to adjust the fan % is to watch what happens to the temp when the fan turns on. If it blows to much then you will see the temp go down and then when the fan turns off you will get a huge temp spike. 30% was the magic number for mine.