Closed oil fired central heating system - Help needed

[BLUEFUNNEL]

Good evening everybody.

I have replaced the circulating pump - Grundfos UPS2, the pressure release valve, the dual Stat, and I have fixed several leaking soldered connections.

I have the system up and running but the water is not circulating.

When i refilled the system, I set the pressure at 1 Bar. I vented the pump and vented the radiators.

The output of the boiler is fed to the pump. The output of the pump feeds the system through 3/4 inch copper pipe. A pressure release valve, an expansion tank, and an air vent are on the line.

The hot water is fed to the top of the house via a manually controlled valve.
The bottom of the house is also fed via a manually controlled valve.
The feed to the hot water tank is also fed through a manually controlled valve.

The pipe carrying the water from the boiler to the pump is very hot at the boiler end. It becomes progressively cooler as it nears the input to the pump. At the output of the pump, it is quite cold.

I presume that there is an air lock in the system. How do I get rid of it.

The pump is running normally. The pressure in the system has risen to 2 Bar.

Do you think that manually operating the pressure relief valve might help?

Any help would be greatly appreciated.

Many thanks,

Jimmy

 

[BLUEFUNNEL]

Update
=====

I succeeded in getting the air out of the system by opening and closing the pressure relief valve a number of times and adding water.

What water temperature should the boiler be run at for normal operation?

Many thanks,

Jimmy