I wonder why the varistream costs so much if the regulator is less than £20?
Because this and other flow controllers also incorporate dead ending control (pressure switch) where these don't.
These are also mass produced, where the Varistream is produced for a specific market in much lower numbers. But on top of your imported controller, you need to add the cost of a moisture resistant box to keep your components dry.
If you are using a controller just to reduce motor speed, hence flow rate, then this has to be connected through the pump's mechanical pressure switch.
The idea of the Varistream was to replace the pump's pressure switch and incorporate it in with the electronics.
We have never had to replace a Varistream in 7 years of using them and have been generally very reliable, so they have well paid for themselves as far as we are concerned.
It comes down to what you want from your system.
As spruce points out the controller does monitor DE water flow stopped and allows the system to operate more efficiently at lower pressure.
This lower pressure puts less strain on the connectors - hose - pump. With a pump running at a lower speed you also reduce the wear and tear on the pump motor and brushes. The slower the pump the less current you use and the longer your battery will last between charges.
We add a voltmeter - allowing you to monitor battery state and to help fault find
A Low battery cut off to extend the battery life
The new control has a low battery over ride to allow you to keep working and finish the days work
Relying only on the pressure switch works for some, bear in mind why controllers came about n the 1st place
1. In running the pump until it hits the pressure switch you are running the pump as hard as it can possibly work. This means that the pressure in the system will be at its absolute maximum. This puts strain on the hoses, on the fittings and on the pump. It therefore increases the chances of split hoses, leaking joints and increases wear on your pump, shortening its life.
2. As the pressure switch cuts out the pump is at maximum, working as hard as it possibly can and therefore drawing maximum current from the battery. Hence as the switch opens it is under great strain. The high current and the fact that the pump is an inductive load (with stored energy) means that the pressure switch contacts are likely to arc and eventually they will fail.
In Short after 7 years continuous development the controller does far more than just control the pump speed.
We produce 1000,s of controls every year ranging from the Analogue - Hot water Charging + others through to the Liquid logic V series and the Specialist 24V DC display panel manufactured for a dutch company.
In The end you have to do what is right for you