Air in header tank

[mjh1989]

Hi, I have air bubbles coming into my central heating header tank via the feed pipe when my boiler is running. I also have to bleed the same radiator every week. I have drained the system and refilled with inhibitor. I also added a magna clean and fitted a new pump due to the boiler cutting out a lot. Since fitting the new pump boiler runs for longer periods but I have had water over pumping up the vent pipe which I have now managed to stop by lowering the speed of the pump. But I am getting a lot of air bubbles coming up the feed pipe into the header tank and the water is turning brown and manky. Any help will be much appreciated.

 

[Ermintrude]

Problems at mill . What condition rads in?

 

[Roger Welton]

The top of my header tank is full of air also.



Fortunately the bottom is full of water

Are the feed and expansion plumbed in correctly?

 

[Whyme]

Have you got any pictures of the cold feed and vent pipe configuration ie in the cylinder cupboard. if it pumps over you aireate the water and it will go manky and the magna clean will have a full time job on. did the feed tank drain when you drained down cos a partially blocked cold feed can cause that. just a thought :smiley2:

 

[mjh1989]

I only have 7 rads in house and two of them are new. the others all heat up ok. With no cold spots.

When I drained the system the tank drained fine. Also since ive lowered the speed of the pump no water comes out the vent pipe.

my vent and feed configuration is a H shape with the vent on the right and feed on the left with the pump situated 400mm below the feed. And below that is the control 3way valve. The feed and vent pipe are 110mm apart.

It seems to run fine and after the boiler has been on for a period of time you can hear air going through the system. Mainly at the pump. And ends up coming up through the feed pipe and into 1 radiator. I have tested the stat on thr boiler yo make sure it wasnt over jeating and it seemed to work ok. When I turned it down to 1 boiler cuts off and when I turned it back up boolers cuts in again.

I will try and upload a picture of my pipe configuration later.

 

[mjh1989]

I have 2 new rads. Only have 7 in the system and all the others heat up ok with now cold areas.

The feed tank drained fine and have looked and there is no longer water coming out the vent pipr since i slowed the pumps speed.

The feed and vent pipes are configured in a H shape with vent on the right and feed on the left with the situated 400mm below the feed pipe. And below the pump is the 3 positon valve. I will try and post a pictur later. The feed and vent pipe are 110mm away from each other.

The bolier runs ok for a period of time and then as system heats up you can hear air running through the system. Mainly around the pump. This is when the bubbles end up coming up the feed pipe and into the radiator I have to keep bleeding.