Air trapped in pipework heating. Can't move it

[Bazza84]

I put the hose pipe in the tank and pushed it against the outlet. It then gave me pressure on all rads.

I had tried from the drain offpoint without luck!

 

[jacobball]

have all radiators got water in them?? vent them to check.

 

[slapper]

there should be no gate valve on the cold feed pipe from the f & e cistner, this is dangerous and will cause pumping over.

try turning h/w and then heating on at the programmer, for about 20 seconds no more, this sometimes draws water in and shifts air from around the pump connection. Is the pump in the loft?

I,m done on this one FFS,never heard such drivel.

 

[Bazza84]

Yeah all rads are nice and full, and pressure looks good!

I have now shut off all rads but 1 to increase flow on flow and return pipe.

 

[Whitespirit66]

Another trick, if you can get some water to circulate and the boiler to work, is to turn the pump down to 1.

Leave it like this for 48 hours, then turn up tp 3. This ofter shifts stubborn locks for me.

 

[jacobball]

I,m done on this one FFS,never heard such drivel.

drivel? it worked in my old system, it got air out of the pump area and allowed the system to then fill.

 

[letsgogreen]

Have you tried shutting off all the rads apart from the one furthest from the boiler? This will increase the flow speed through the rad and hopefully drag any air to it ready for you to then bleed later. Switch on the next furthest rad and then turn off the other one. Proceed like this util each rad has had it's turn as only rad working. This usually does the trick. Then bleed all the rads Good luck.

 

[jacobball]

sometimes I have heard drawing air from a return pipe (clamp on drain valve can be used) can draw trapped air from a CH system. May be worth a go?

 

[TicklyT]

I put the hose pipe in the tank and pushed it against the outlet. It then gave me pressure on all rads.

I had tried from the drain offpoint without luck!

If that's the only way you can get water into the system, that should be telling you something about the state of the connection between the F&E tank and the rest of the system.

 

[nogoodatfaultfinding]

In your cylinder cupboard there will be three pipes connected !!!

The Flow, The Vent and the Cold Feed.

YOU HAVE A BLOCKAGE IN THESE PIPES WHERE THEY CONNECT!!!!!!!!

Cut out and replace this section!!!!

Try turning the pump down and you will still have the blockage.

Try leaving only the last rad open and you will still have this blockage.

Pump as much mains pressure through a hose or whatever you want and you will still have this blockage.

Heres a bad tip for you, chuck some x800 in leave it a few days and then power flush and i garantee you will still have this BLOCKAGE!!!!!

Cut out the section and replace with new pipe!!!

Hey presto no blockage and Heating works fine!!!

 

[Bazza84]

This section,

would it be by the cylinder. I can see 3 pipes one they all join up to a diverter.

Thanks for your advice, I turned down pump to one and it's now trying to heat.

Not sure if this still means there is a blockage

thanks to you all for your time

nogoodfaultfinding if you can give me some more info on the 3 pipes that would be great

 

[Hugh Jaleak]

Find the flow pipe from the boiler in cylinder cupboard, does it go into an arrangement of pipes, or a small round 'barrel' type thing, (air seperator)? Should have flow from boiler, vent to over F+E, cold feed and then feed to pump. Blockage will likely be here. Cut this section out, clean and refit.

 

[nogoodatfaultfinding]

Follow pipes back from small FE Tank to Cyilinder cupboard.

You should have 22mm Vent (Up and over Tank), 15 mm Mains cold feed (From Tank) and 22mm Flow Pipe (Direct from Boiler which will connect to pump)
These 3 pipes will all join at one point (not in any motorised valves).
You should if plumbed properly be able to dissconect from pump and cold feed at the unions and just cut at the vent then replace all that pipework.

This will undo your blockage.

 

[Bazza84]

Ok I will have a look, as it is I can see the pump but fear the pipe u mentioned joins under the floor board.

So I am looking to just replace the vent pipe? Can I not just flush that pipe by undoing it and running a hose through it?

Thanks

 

[nogoodatfaultfinding]

Can I not just flush that pipe by undoing it and running a hose through it?

You are likely to have enough sludge in there that a power flush wont shift it and even if you do you will only likely shift it into your heat exchanger.

Just replace the lot!!!