More Heating Headaches!

[Thomarse]

Hi,

I just tried to add some Fernox to my system... I added it to the header tank... then started to drain some water from the bottom of the system (the lowest radiator in the kitchen with a bleed valve)... water came out of the valve,, but nothing happened in the header tank, no water drained from there back into the system at all.... Therefor no fernox has entered my system.

I now have a huge airlock. the last time I drained my system, the only way to get rid of the airlock was to attach a mains hosepipe to the valve on the kichen radiator and pump water back up through the system, after a few times this worked and the airlock was released. However, thinking back to that, when I pushed water back up through the system, the water came out into the header tank via the hot water tank overflow pipe....Does this make any sense? should it of not have come up through what would normally be the outlet hole in the header tank?

Obviously I can fix my airlock in the same way using my hose...But my worry now is that the system isnt being topped back up by the header tank... could it be blocked? Am I missing something?

My logic was that when water was drained from the bottom radiator of the system, that the system would be topped up by the header tank, thus taking the fernox with it....but as mentioned. no water left the header tank thus creating the airlock...

Any advice would be gratefully recieved as this puzzle is doing my head in!

Tom

[Heliotrope Smith]

How much water did you drain off from the header tank?

Have you tried switching the heating system on?

If you are not confident then switch off the gas supply to the boiler and switch between hot water and heating. Vent air through the vent screw on the pump.

If you drain any more water from the system then drain it into a bucket and put back into the header tank.

[Thomarse]

I draine about 1 large bucket full... then no more would drain.. due to air lock I guess... But I thoght once you started draining water from the bottom of the system the header would start topping it back up??

No I hvaent switched it on as I am worried as I hve drained water out.

I dont understand what you are saying about the gas supply to the boiler?

Tom

[Mike Clarke]

Any chance you've got the two tanks confused?

[jontelfer]

I think I had something similar - limescale plug blocking the feed pipe from the header tank to the rest of the system. Seems to fit your problems. Likely blockage location was behind the immersion tank so the solution was to cut the feed pipe (and cap off) and join into the expansion tube.

Good luck

Jon

[Heliotrope Smith]

If you have not switched the system on you cannot know if you have an air lock. Switch the heating on, most likely you would hear sloshing and gurgling then the system settle down and work ok. The worst that will happen if you have an air lock is the boiler will cut out after a short time.

[Thomarse]

Just an update,

It was a blocked cold water feed, Luckily there was a manual valve just above the T juntcion so I undid this and poked out the solid gunk... Flushed the system through and all appears to be working fine again now!

many thank

tom