Central Heating - Flushing or Cleaning

[GasMan1965]

I eat my words then coz it sounds like an air lock

Have you tried bleeding with the pump on full as that can pull it through !!

When you drain is the tank in loft empty ?

 

[smudgersmiffy]

Pump is in a really difficult to get to place, so haven't been able to put it on full speed (although it could be on full already!).

Yes, when I drained down, the tank emptied completely.

 

[GasMan1965]

Put it on heating only and turn off all rads apart from the furthest upstars,, with pump on try bleeding !

 

[Whitespirit66]

OK, so air lock then!

You really need to bleed the pump, as shifting the air trapped in it will make it more efficient. This on its own may be enough to sort your problem.

Here are my methods for shifting air locks, quickest method first:

1) Turn pump speed to max, and close downstairs rads.
OR
2) Drain system and refill with a hose pipe attached to the lowest drain point (sometimes near pump), or push hose pipe down outlet hole in bottom of F&E tank.
OR
3) Turn pump speed down to min, and run system for a few days. Then turn pump to max and close all valves on working rads. Have used this method several times as a slow but effective way to clear locks.

 

[foley74]

Why ? not get a bit of hosepipe,push it as best you can over thee ball valve and into the cold feed,if you cant do that then try and get mains pressure into the cold feed,it will force any air out and refill the system.I was sick of trying to fill systems back up,so i made a connection that fitted over the ballvalve water outlet and then went down into the cold feed connection,pressed the ballvalve down and all proplems sorted,it makes life easy

 

[The Baker]

This has worked for me.

I had a job in a house in which the heating had been extended/altered over a period of years.

It was a sod to refill if I was working there alone. He got fed up with the bleed time/costs.

There were four rads down stairs and five rads upstairs.

Thats nine rads.

As the bloke had six kids aged 10 to 16 I suggested plan B.

His kids had a bleed key each and were instructed to stand by their bedroom rad.

The customer and his wife and I were down stairs they had one rad each and I had two to watch.

I turned the cold main back on, the down stairs rads filled quickly.

We ran up stairs to keep an eye on the kids, and it all filled up with no trouble.

How many kids have you got?

Tim.

 

[GasMan1965]

What he could do is leave the bleed nipple open on the furthest upstairs rad then refill while watching just that rad then bleed the rest once water is @ the 1st

 

[smudgersmiffy]

So what you're suggesting is to somehow connect up (on a temporary basis of course) from the cold main, directly to pipe that comes out the bottom of the expansion tank.

Open the bleed screws on the upstairs rads, and wait for all the air to come out.

Doing this, the mains pressure water should force the air into the top of the rads, and then expelled through the air valves?

Once the air's all gone, close the bleed screws, remove the temporary pipe arrangement, and Bob's your uncle?

 

[GasMan1965]

Put ya garden hose on a downstairs drain cock with a jubilee clip and fill it form there