Massive air lock??

[bradley_stoker]

Hi Guys,

I am new to this forum but would welcome your ideas. I am not a plumber, but reasonally competent at most DIY tasks...if I can be asked!

Last weekend I re-fitted our lounge radiator folowing redecoration.

A few days before I had run the system without this rad and all seemed well.

I bled the radiator and thought no more of it. Later that evening (with only the hot water on -24/7 as usual) there was a terrific schreeching sound that seemed to be coming from the boiler pipework....like surround sound in a bad movie. It seemed like water was perhaps boiling in the boiler (in kitchen). I switched the hot water off and it went quite after a moment or two.

I then investigated the situation and checked the upstairs radiators. All needed bleeding which I attempted to do.

This is where the plot thickens....I attempted to bleed them but there was no air expelled and they all seemed part empty.

On checking the header tank there was water at the usual level, but no obvious sign of any change in level.

I seem to have a major air lock somwhere, I have tried blowing down the vent pipe as one of my colleagues suggested but to no avail.

Two of the upstairs radiators will now get hot and the noise has not come back even with hot hot water and heating left on for a couple of hours.

The two that are hot are the ones that seem to work on gravity, all othes are stone cold. The pump is not circulating the hot water, although it is making it's usual intrusive drone!

Any ideas as to how I can bleed the sytem?

your comments would be much appreciated.

regards

Bradley Stoker

 

[wilhelm]

blocked cold feed?

a search will uncover a few thousand hits.

 

[bradley_stoker]

I don't think so, there is some sediment in the tank but the outlet is well above that, also I poked a piece of flexible wire down the outlet.

 

[wilhelm]

well thats ok then

 

[ollski]

I don't think so, there is some sediment in the tank but the outlet is well above that, also I poked a piece of flexible wire down the outlet.

It will block where the feed pipe tees into the system pipework or close to it.If you leave it an hour and can then bleed a small amount of air which comes to a stop, then repeats after an hour it will be a blocked cold feed. A temporary fix to get around it is to get a small piece of hose and stick it as far round the vent pipe as you can then hold the other end onto the ball valve and back fill it.

 

[bradley_stoker]

Thanks for that....I will attempt a reverse back fill tomorrow evening. It seems to me that a blocked feed is a likley solution.

I will report back.

Bradly Stoker

 

[chrishutt]

Another "likley solution" (likely problem) is that the pump has failed. Can you check that?

 

[bradley_stoker]

Thanks...the pump appears to be working...well making a noise anyway....I prefer the earlier problem (solution!)

Bradley Stoker

 

[Nige F]

Fill it upthrough a drain cock downstairs with someone watching the level in the expan. tank. And someone going round bleeding rads..Fun for the whole Family