Hi,

I've recently been mucking around with my Rocket and have got to the point where I want a second (or more) opinion. Up until recently, I had a float valve in the reservoir, which actually worked perfectly, but it just wasn't permanent enough for me.



I decided to rip it apart and install some extra bits to plumb it directly in. This is all working fine - my problem is that the OPV return fills the reservoir at about 15% per day. I knew this would happen, but not to this extent, and I don't really want it to be able to be 'forgotten about' and overflow everywhere. What I'm curious about is if I can reroute the output of the OPV back in to the inlet of the pump, without any negative implications.

It goes: mains supply > regulator (~0.75 bar) > filter system [at this point enters the machine] > inlet solenoid (opened when pump is active) > pump. There is another inlet solenoid back to the reservoir controlled by the switch, making it easy to switch back to tank water.





Thanks in advance for any comments.

Nice work there!

I have no experience doing that (teeing the OPV outlet back into the water line upstream of the pump) but have seen it discussed on the forum ( OPV return options ) and believe it's been done on similar machines. Seems sensible.

You may want to back the OPV off a bit - with a couple bar of line pressure working in the same direction as the OPV spring you would expect about that much more pressure in the HX when it starts to open.

Thanks for that - I had a few ideas after posting.

I did connect the OPV return back into the inlet, which worked, but was a lost cause because the airlock/priming valve was still feeding a reasonable amount of water back in to the reservoir anyway. I obviously couldn't feed that back into the inlet.

I went with something I thought of soon after the first modification (but couldn't be bothered actioning). I made the selection between reservoir and mains automatic; I built a simple water level sensor that measures how much water is in the tank and if it goes above a threshold, the draw is automatically taken from there. Once it goes below another (lower) threshold, it switches back to mains.

Now, the switch simply selects whether to revert to mains when the tank is empty - I know this shouldn't really happen, but if at some point I am using it on a tank water and the tank goes empty I don't want it opening the mains solenoid because all the water in the line will bleed on to the bench!

With this working, I was able to make the OPV and airlock/priming valve feed back into the tank as usual and not worry about too much water collecting in there.

A few photos attached... don't really show much but you get the idea.