Replace Heating Pump?

[Retroelec]

Hi
Our radiators downstairs don't heat up very quickly and sometimes not even at all if the top floor ones are on.
The boiler is a GlowWorm Micron 50ff and with all the radiators on it needs to be reset quite regularly which I assume is because it is getting too hot?
The system is an open vented S plan with only 1 heating zone and the pump in the airing cupboard upstairs, heating valve and actuator have been changed in the last 5 years and the pump is as old as the install approx 25 years?
I am pretty confident that there is no air in the system and balanced OK so would the next idea be to change the pump?
The pump is a WILO Gold 50, I have checked its not seized by removing the center screw but it rattles a bit when running and gets too hot to touch.
Any other ideas it seems to be the same on all speed settings?
Thanks

 

[ShaunCorbs]

Pump when you pull the bleedscrew out can you stop it with a screwdriver (you will see the impella spinning) if you can stop it easy new pump required

 

[king of pipes]

I would fit a new pump 25 years is along time and it's done well considering its on a open vented system. Kop

 

[Reddwarf4ever]

I had a wilo gold 50, just wouldn’t pump,enough, very noisy and as you ha e noticed gets very hot.

replaced with a DAB Evosta, very pleased with this pump.....check my posts for details. Found a very good price, can give details if interested.....Also runs very cool, almost silent and performs very well....