A slight delay is normal.
When 1st starting or coming out of DE (Flow stopped) Spring manufactured controllers need to be able to differentiate between Flow stopped or Flow on. To do This our controllers carry out a test to check for flow. When in DE this test occurs every three seconds also when you switch the unit on at the begining of a job/day the control will have been sat in the DE test mode.
So depending at which point in the test cycle the controller is as you either switch on or open a tap it may take a brief moment for the pump to kick in. As the test cycle is short chances are you will rarely wait for three seconds, one to two as you note is probably more normal.
Another factor particularly at the begining of the day is pressure dynamics of the hose and system when you first connect the hose and switch on the hose wall expands and the system has to pressurise this may take a few seconds for pressure generated by the pump fills the hose line and you see water at the brush head.
You will notice less delay in flow restarting if you have dead ended the pump during a job, this is because the hose line remains pressurised.
We could shorten the DE retest cycle slightly however there will be a second or so delay as the control needs to be able to diffentiate between states.
The Micro DE testting the controller does is also designed to ensure that the presure can not build up in the system while the pump is in DE this help protect connectors, pump, and hose line .
Our controllers are perfoming a number of system safety checks continuously most of them you would not even notice. These are the value added features and a combination of a number years development. This development is an ongoing part of what we do.
