Trapped air in pump!

[markirv]

I have a Eurostar oil fired boiler which was installed with a new central heating system 3 years ago.
Around 1 month ago the hot water and heating were not heating up sufficiently. I finally tried bleeding the pump, first with the pump off which let a little air out and then with the pump on which expelled lots of air, I could hear the gurgling of the water starting to come through, and this fixed the problem.

The problem now is that every night when I put the heating on, I have to bleed the pump again after 2 or 3 hours of switching it on. It is then ok until the next night. The pump is at a higher level than the radiators which may account for the trapped air but where could the air be getting in? and why has this only started to happen recently?

Any help would be most appreciated,
Mark

 

[taydo]

is it air or hydrogen?

has the system been regularly serviced and topped up with inhibitor.

if not it could need flushing and re dosing with inhibitor.

 

[markirv]

It is air and hasnt been serviced since it was installed. Can you tell me what the inhibator does?

 

[ChrisR]

It passivates (coats with a nonreactive compound) the surfaces of the iron parts of the system so they won't corrode.
I would add that, also look at the pipework - air gets produced in the boiler , can it get out of the vent before getting to the pump? Which way up is the pump? Maybe you need an aoutamitic air vent, but be aware that if the pressure goes negative when the pump starts, air will be drawn in. (That could be happening anyway through a "micro leak" which will let air in but not water out.)

 

[sterose]

is it air or hydrogen?

has the system been regularly serviced and topped up with inhibitor.

if not it could need flushing and re dosing with inhibitor.

Hydrogen?

Seriously, since when does anyone have hydrogen in their system?

If you are referring to the post on this forum about to Hydrogen in CH systems, it was a one off, and we never found out whether it was even actually Hydrogen.

For the record, Hydrogen is not found in domestic CH systems.