Air in the System

[Potatoman]

Hi, how do you eliminate stubborn air in the heat pump system when you have a single zone system.

[The Bin Man]

If it’s that bad you need air tap(s) installing.

[JohnMo]

Having air traps at all high points, then you have no stubborn air traps.

 

UFH loops blast them with tap water one by one.

[Potatoman]

10 hours ago, JohnMo said:

Having air traps at all high points, then you have no stubborn air traps.

 

UFH loops blast them with tap water one by one.

If I did that idea, how do I get glycol back in the system 

[JohnMo]

I used a filling flushing point and pumped it in with a hand pump.

 

But no longer use glycol, just inhibited water. Glycol is rubbish and generally not needed.

[JamesPa]

Time is another key factor.  Dissolved air comes out of solution quite slowly, mine (for example) took a full month.  Sometimes you need to be patient.

[Potatoman]

10 hours ago, JohnMo said:

I used a filling flushing point and pumped it in with a hand pump.

 

But no longer use glycol, just inhibited water. Glycol is rubbish and generally not needed.

That's interesting, where did you position it and how did you get to drain/fill the hot water tank.

[JohnMo]

5 minutes ago, Potatoman said:

That's interesting, where did you position it and how did you get to drain/fill the hot water tank.

Hot water tank? Is this a buffer or volumiser?

 

I positioned in the return to heat pump.  The way it works close the lower valve with circulation pump off.  You then open the other valves, inject into one port and water ejected from the other.  You add the correct amount of glycol and close the valves and open the bottom one again.  Circulate system.

 

But as mentioned, as would do everything I could to eliminate the use of antifreeze.

[Nickfromwales]

30 minutes ago, Potatoman said:

That's interesting, where did you position it and how did you get to drain/fill the hot water tank.

The hot water tank has a coil which heats up the water that comes out of your hot taps. The 2 are completely separate hydraulic circuits.

 

Would you like to post some pics, half a dozen or so, so we can see what’s going on and spot any obvious faux pax?

 

Someone on here a week or two back was about to start open heart surgery and I just said bleed something for 5 seconds, problem gone at £0. 

[Potatoman]

48 minutes ago, JohnMo said:

Hot water tank? Is this a buffer or volumiser?

 

I positioned in the return to heat pump.  The way it works close the lower valve with circulation pump off.  You then open the other valves, inject into one port and water ejected from the other.  You add the correct amount of glycol and close the valves and open the bottom one again.  Circulate system.

 

But as mentioned, as would do everything I could to eliminate the use of antifreeze.

Thanks for that, I have a buffer and separate hot water tank, my worries are after flushing the system and refilling I end up with air in the system like the buffer tank,hot water tank or the circulating pump. Would all this trapped air eventually make its way to the automatic bleeding valves.

[JohnMo]

5 minutes ago, Potatoman said:

Would all this trapped air eventually make its way to the automatic bleeding valves.

Only if the bleed valves are at any high points

[sharpener]

1 hour ago, Potatoman said:

Would all this trapped air eventually make its way to the automatic bleeding valves.

 

Yes but the key word is "eventually" as @JamesPa implies upthread.

 

If individual radiators gurgle or do not get warm all the way to the top turn off all the others to force the air out, doing them one at a time.

[Nickfromwales]

1 hour ago, Potatoman said:

Thanks for that, I have a buffer and separate hot water tank, my worries are after flushing the system and refilling I end up with air in the system like the buffer tank,hot water tank or the circulating pump. Would all this trapped air eventually make its way to the automatic bleeding valves.

Ok. 
 

Do you know what a bleed nipple or AAV / automatic air vent (aka bottle vent) look like? 
 

We need to know if you have these, and where they are. 
 

2 hours ago, Nickfromwales said:

Would you like to post some pics, half a dozen or so, so we can see what’s going on and spot any obvious faux pax?

What he said   

 

When we see a pic of your UFH manifold and adjacent / connecting pipework we will see if you have isolation valves on your UFH manifold. 
 

If so, you shut the system down and switch these off. Then you purge the UFH loops with cold mains (a couple of hosepipes required for this) and then open those valves back up to recommission.

 

The buffer should have a vent or AAV at the top.

 

Hot water cylinder should be less of a concern. Leave that out of your enquiries for now

[JamesPa]

13 hours ago, JohnMo said:

13 hours ago, Potatoman said:

Would all this trapped air eventually make its way to the automatic bleeding valves.

Only if the bleed valves are at any high points

Even if the bleed valves are at the high points air can still get trapped elsewhere.  I have a tall radiator downstairs, well below the auto bleed valves, which needed manual bleeding every two days for a month after my ashp installation was done.  That's why radiators have bleed points!

Edited 13 hours ago by JamesPa

[JohnMo]

2 minutes ago, JamesPa said:

have a tall radiator downstairs, well below the auto bleed points

But aren't all radiators forming a high points, unless radiators tails come down from the ceiling?

 

Any changes in elevation upwards that then comes down again is an air trap, so needs a bleed point.

[JamesPa]

4 minutes ago, JohnMo said:

But aren't all radiators forming a high points, unless radiators tails come down from the ceiling?

 

Any changes in elevation upwards that then comes down again is an air trap, so needs a bleed point.

100% agreed. 

 

But few will fit auto bleeds on every radiator and @Potatoman was asking if air would find its way to the automatic bleed valves.  My reply was no it won't, you may need to use in the manual bleeds on individual radiators in addition to whatever automatic bleeds you have.  

Edited 13 hours ago by JamesPa