Sorry for late reply, didn't get any email notification(s) of your posts.
Will read the above in more detail later.
You have a sealed system so you will have the same pressure throughout the system and it will be at the EV pressure (with allowance for elevation) so if you were to attach a pressure gauge to any part of the system then you should get 1 to 1.5bar?? pressure, makes me wonder (again) where it joins the system exactly. Unless the system is 100% blocked in places then you should feel that pressure if you hold your finger over any point of opening, if there is a blockage then yes the flow will reduce to a trickle once you remove your finger.
When you were testing/flushing, how did you keep the EV pressure at 1/1.5bar?. also whether flushing with the EV or mains, ( not a bad idea), ensure the 3 port valve is, preferably latched in CH position but if not, latch it in mid position.
I would be very surprised if any one of those two pumps is knackered, if the impellers/pump ports are clear and you are getting the power associated with the mode settings and flows, and you were, then nothing wrong there IMO.
Where does the EV outlet join the system, is it before the pump?, you might remove it where it joins the system and ensure clear.
Will read the above in more detail later.
You have a sealed system so you will have the same pressure throughout the system and it will be at the EV pressure (with allowance for elevation) so if you were to attach a pressure gauge to any part of the system then you should get 1 to 1.5bar?? pressure, makes me wonder (again) where it joins the system exactly. Unless the system is 100% blocked in places then you should feel that pressure if you hold your finger over any point of opening, if there is a blockage then yes the flow will reduce to a trickle once you remove your finger.
When you were testing/flushing, how did you keep the EV pressure at 1/1.5bar?. also whether flushing with the EV or mains, ( not a bad idea), ensure the 3 port valve is, preferably latched in CH position but if not, latch it in mid position.
I would be very surprised if any one of those two pumps is knackered, if the impellers/pump ports are clear and you are getting the power associated with the mode settings and flows, and you were, then nothing wrong there IMO.
Where does the EV outlet join the system, is it before the pump?, you might remove it where it joins the system and ensure clear.