New pump problems

[1spaceboo]

I have had to replace a seized Grundos CH pump with a Wilo gold 50, the problem is that when I have tried to get the heating back on, after filling and venting the system I have no flow of hot water to my rads. The pump is running as I can hear the noise change when the speed is changed, inlet and outlet valves are open, the motorised valve is opening when it should do, all I am getting is a hot pump and hot pipework around the pump. I have also vented the pump using the centre silver vent plug.
There is an arrow on the casing of the pump showing direction of flow, so the pump should be installed correctly.
Any suggestions would be greatly appreciated.

 

[BingoBongo]

sounds like air or a blockage

vent again/double check valves are open Are they gate valve type ??they could be snapped shut!!

stick screwdriver into pump to kickstart it

did you fit the arrow the same way as the other pump?

 

[gassafeman]

Have you vented the h/water circuit?

If so, how? Oh and why put a Wilo in?

Paul

 

[1spaceboo]

Yes they are gate valves, and I did wonder if they weren't opening properly, I may opt to replace them tomorrow. Yes I put the arrow pointing the same direction. I haven't been tempted to take the vent plug fully off the pump when running because of the water jetting out!

 

[1spaceboo]

I haven't vented the Hot water circuit as I haven't really touched it and it was working fine beforehand.
I put in a wilo pump because it was given to me.

 

[BingoBongo]

put a towel down and vent the pump properly
stick a driver in to make sure its spinning

 

[1spaceboo]

I can hear the pump spinning, and I don't fancy getting scalded. When I turned off and let the system cool down I took the vent off fully and got covered, it was ok with warmish water but not hot water! When I took it off I used a screwdriver to turn the pump freely.

 

[BingoBongo]

i`ll stick a virtual fiver on pump valves

 

[glasgowgas]

as gassafeman and bingo have already said, vent everything first

switch off htg so nothing is running (boiler and pump)

run round rads for a quick vent

vent hw cylinder htg circ

vent (not running) pump, check its free

now give system a run

 

[kevplumb]

When I turned off and let the system cool down I took the vent off fully and got covered, it was ok with warmish water but not hot water!

bearings have got to be going

 

[steve32]

cold feed blocked, lack of water in system