Central Heating air bubbles appearing in FE tank
 

Hi All,

Before I ask my question - Have a great New Year!

I've been having a few issues with my central heating, I cannot run my
boiler on full heat because the over-heat switch keeps kicking in -
turning my boiler off. If I turn the pump up to full speed (from
medium), water begins to come out of the over hanging vent pipe. A
friend advised me that I may have a partial blockage in the pipes
around where the boiler flow, feed, expansion, and pump inlet pipework
is. He suggested that I use DS40 to cleans the system.

I've now added the DS-40. My rads get real hot, I can now run my pump
in full speed and water doesn't (at the moment) pour through the vent
pipe. However I keep hearing bubbles coming up through the FE tank. I
believe they are entering through the pipe that normally fills the
central heating (my system is Open Vented, fully pumped) - this pipe is
also hot, further suggesting the fact that water is traveling up this
pipe.

Can anyone suggest what is causing this, if its normal during DS40
cleansing (I only put the cleanser in approx 24 hours ago) and how I
can get rid of it.

Kind regards,


Danny