Help airlock in heating system

[Russell1982]

Hi

I just changed the rad in a mates bathroom to a towel rad, I froze the pipes so I didn't have to drain the system,

When the rad was fitted it only filled halfway air stopped coming out bleed valve . Thought it was weirded but shut the valve to the rad and started the heating but the pump sounded funny.

Sounded like air in the pump so stopped pump bleeded but no water dribbled out, started heating up again sounded like it was pulsing the water but pump running fine,

I undone the bleed valve in the airing cupboard and I little air came out but was pulsing with the pump.

Do u think that the feed from header tank is blocked ?

I have tried to budge the air every way I can think. But not the pump sounds dry and no air coming from anywhere

If it is blocked can I just back fill it from the a drain down valve above the boiler? None on the rads down stairs

Hope u can help. Got little baby in house so they need a bit of heat too

Oh I should say I have no heating or hot water

Cheers

 

[45yearsagasman]

For starters the pump should be OFF when venting air, and it does sound like a blocked cold feed. Back filling is a way out for a bodger. Find the cold feed connection and clear it, you know it makes sense. If you have a freeze kit then it should be a doddle.

 

[Russell1982]

Hi I know it's not the correct way but to get to the joints they are at the back of the cupboard about 2" away from tank and its all soldered joints


If I back fill it for now to get the system going again for the baby. What's the best way. The lowest drain valve is above the boiler

They are going to change all the rads in the summer next year so will get the system flushed as there's loads of bits in the system

Cheers for the quick replies and help

 

[mcmoby69]

have you actually looked at the header tank?

could be the ball valve is stuck shut and needs a clout.

 

[Russell1982]

Yea I did that. All full and ball valve works too. First thing I checked

 

[xr4x4]

Way to check blocked cold feed is to turn off supply to tank, drain system a little and the level should drop.

 

[Russell1982]

Yea it blocked

What's the best way to back fill the system ? Need heating on as baby in house and plumber not free till a few days

Cheers

 

[Nige F]

Someone in loft watching feed tank water - then backfill through any drain cock .

 

[xr4x4]

I'm guessing that as its blocked it won't rise though the feed?

So it will come through the vent?

 

[Russell1982]

I guess it will. Tho thinking of calling plumber to unblock feed