6m pump only going to 4m max setting

[Best]

Wondering if I have a faulty pump?
On variable speed or fixed speed settings it will only go to 4m.
If I set it to max variable, 6m flashes and then goes to 4m

 

[ShaunCorbs]

is it auto adjusting to a restriction ? eg getting too much back pressure so its knocking it self down ?

 

[Best]

is it auto adjusting to a restriction ? eg getting too much back pressure so its knocking it self down ?

That was my thoughts, but on fixed speeds, at C3 max setting, it still only goes to 4m.
The system is a bit suspect of blockage and that was the reason I replaced the original pump.
I would have thought it should be 6m, regardless of any system issues.

I had no time to do anything else.
There is a bypass valve might be worth opening fully to test if pump changes

 

[ShaunCorbs]

i would open it worth a test

what pump is it?

 

[Best]

It is identical to this pump, only goes under different brand names.
https://www.NoLinkingToThis/p/flomasta-central-heating-circulating-pump-230v/45357

 

[sammathias]

Altecnic one?

 

[Best]

Altecnic one?

Yes, that’s the one.