Air gettinging into the CHS - particulalry following a bath??

[jlheath]

Hi,

I have noticed recently that a small amount of air is getting into my central heating system in the form of small bubbles collecting in my bedroom radiator. This gets a lot worse if a bath is run. Sometimes an almightily banging can be heard throughout the central heating system seemingly emanating from the boiler. This lasts a few seconds only.

I have reduced the pump speed on the system which has made things better. Unfortunately if I reduce the pump further the central heating does not effectively operate in that some radiators don not fully heat up. The central heating system uses the small bore flexible copper pipework (10 mm?)

I have a 12 year old house with a cylinder tank. There are two tanks in the loft so I believe I have a standard vented system.

I have fitted several new radiators in the last few months but there are no water leaks visible and I am pretty confident that all connections are good.

Can anyone suggest a possible fault or further investigations I can do?

Thanks

James

 

[buffy27]

Hi,

I have noticed recently that a small amount of air is getting into my central heating system in the form of small bubbles collecting in my bedroom radiator. This gets a lot worse if a bath is run. Sometimes an almightily banging can be heard throughout the central heating system seemingly emanating from the boiler. This lasts a few seconds only.

I have reduced the pump speed on the system which has made things better. Unfortunately if I reduce the pump further the central heating does not effectively operate in that some radiators don not fully heat up. The central heating system uses the small bore flexible copper pipework (10 mm?)

I have a 12 year old house with a cylinder tank. There are two tanks in the loft so I believe I have a standard vented system.

I have fitted several new radiators in the last few months but there are no water leaks visible and I am pretty confident that all connections are good.

Can anyone suggest a possible fault or further investigations I can do?

Thanks

James

what s the craic.
what type of boiler [oil ,gas,combi,etc]
what kind of heating/ hot water controls
are there 2 plastic storage tanks in the attick,a copper cylinder in hot press and a boiler[making hot water and central heating water] some place else.
how long is the problem goin on.is this the first problem.has any thing been altered on system of late.

 

[jlheath]

Hi,

Not sure what a craic is but....

The CHS has a gas boiler (non combi) electronically controlled with independant hot water and heating controls. There are the two plastic tanks in the loft (on larger than the other) and the cyclinder is copper. I am confident it is a primary and secondary system (which makes the bath usage introducing air in the the heating system bizare!)

I have replaced two rads for similar sized versions using flexible ruber piping for one of these. Only other change is having more batshs due to the arrival of our first child last month.

Hope you can shed some light on the hot water usage introducing air into the heating circuit...

James

 

[stevetheplumber]

most common cause of almighty banging you describe is a non reverseable trv fitted in the wrong direction if you look at the body of a trv theres an arrow cast into it if the valve is reversable it will have a arrow head both ends
if you find you have non reversables the flow must be in the direction of the arrow you can tell which way its flowing by seeing which end gets hot first

 

[buffy27]

Hi,

Not sure what a craic is but....

The CHS has a gas boiler (non combi) electronically controlled with independant hot water and heating controls. There are the two plastic tanks in the loft (on larger than the other) and the cyclinder is copper. I am confident it is a primary and secondary system (which makes the bath usage introducing air in the the heating system bizare!)

I have replaced two rads for similar sized versions using flexible ruber piping for one of these. Only other change is having more batshs due to the arrival of our first child last month.

Hope you can shed some light on the hot water usage introducing air into the heating circuit...

James

whats the craic [gaelic for like fun/buzz.i m irish] how long ago did it start happening.maybe this system needs an air seperator/air vents introduced to system. would really need to see the way the house is plumbed. difficult to access . some boilers are not plumbed correctly in relation to controlls.
u say u used a rubber pipe for a rad,can u explain this,it may be drawing in air. the point at which u first noted the problem may be key to a solution here, in relation to works carried out.