How does air get into my central heating system?

Question

My sealed condensing boiler system needs bleeding of a small amount of air every several days. Where does it get in?

Answer 1

Hi, Air doesn’t get in as such it's created by the water reacting on the pipe work and gas is produced by electrolysis. A bit like a lead acid car battery on charge. (You might notice a sulphur like smell (rotten eggs) causes by hydrogen and sulphur ( from the copper)when you bleed your radiators. Also as you heat water to boiling point gases are released from the water. The treatments you can add to the system help reduce these effects. Hope this helps

Answer 2

Air In Central Heating

Answer 3

Perhaps it because you are not bleebing the air out of the rads properly. To do it correctly, you must switch the boiler off. Next wait 10 minutes for the system to settle. As you vent the air from each rad, you must check the water pressure after each rad, and top up as necessary. That might improve things. If it doesn't, then the only way any air can get in a sealed system is because you have a tiny leak somewhere. or the pressure relif valve could be faulty but try what I suggested first as to bleeding the rads correctly.

Answer 4

A small ammount of air is expected in sealed combi type systems this is hyrogen produced by boiling, you can smell it as you bleed , but if you are bleeding every few days , is your pressure gauge dropping , leaving it does it cut off due to low pressure?, if so you have a leak check by boiler heat exchanger unit( permanent pain) and rest of system .Adding fresh water to your system as you are doing , will shorten the life of boiler,radiators everything &cause sludge or lime build up, dependant on which area you live , waterwise hard or soft hope this helps good luck

Answer 5

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RE:
How does air get into my central heating system?
My sealed condensing boiler system needs bleeding of a small amount of air every several days. Where does it get in?

Answer 6

you have a leak at a join either in the boiler or in a non gravity reliant piece of pipe work!!

Have you been messing with the pipes?!

If there is no water coming out I guarantee you you have a joint warped.

If you know plumbing happy days otherwise dont guess get a pro in!!

Answer 7

Sounds like you need to talk to a specialist. I don't know why you'd have to do that manually nowadays unless you have an old system.

Check out the How Stuff Works website and see if it has anything that helps:

http://home.howstuffworks.com/how-to-troubleshoot-a-hot-water-and-steam-distribution-system.htm

http://home.howstuffworks.com/heating-and-cooling-system-basics-ga.htm

Answer 8

if it is a sealed system you have a leak some where , if it is a open syestem this is just natural you will get air in from time to time.