How do I bleed a CH pump?

[spooky_b329]

No, the pipe leaving the pump (22mm) goes under the floor boards where it presumably connects to the radiator circuit. From the floorboards I've had up it looks like the entire rad circuit is 15mm pipe. (5 rads)

 

[spooky_b329]

The pipes for the upstairs rads drops down and under the ground floor floorboards with no connections in the airing cupboard or behind the boiler itself.

 

[hi-spec plumbing heating]

so this is where you must have an airlock cause air don't go down hill

 

[spooky_b329]

So your saying its almost certainly an airlock in the pump? So whats the best way to solve this, close the two valves either side of the pump, remove the four bolts and remove pump, then crack the two valves slightly to bleed off the air? When I refit the pump this will still be full of air, would this shift itself?

 

[hi-spec plumbing heating]

no that would be to check the pump is working but you say it is.

i would get a bowl find the outlet from the pump (the cold side) and slacken the nut on the pump. not the large one the small one, only one or two turns .
cause thats going to be hot then should be able to pull the pipe slightly to release the air and maybe some water.

 

[spooky_b329]

Thanks...fingers crossed...

 

[spooky_b329]

Woohoo!

Thanks...took some nerve undoing the smaller of the two big nuts (one was approx 50mm, smaller was around 30mm) but it worked, got quite a bit of air out and rads are now lukewarm, boiler is firing so hopefully they will get hot soon.

Next time the system is cold I'll see if I can get any more out unless you think this will get pumped round and collect in the radiators?

First time the heating has been on this year...was flipping cold at the beginning of last week!

 

[hi-spec plumbing heating]

keep a eye on the boiler that it keeps running for a few hours and any air left will be pushed out to the rads etc .
next time you drain system i would install a bleed valve on that section of pipe saving all that agro.

 

[hi-spec plumbing heating]

undoing the small nut a few turns the pipe won't come right out because of the olive holding it.