Always lots of air in our CH system

[Richtop8]

When I turn on our CH there's a lot of noise from one specific part of the system - the pipes on the landing, and one radiator. It sounds like air, and the landing radiator needs bleeding regularly (about once a month), even though it isn't the highest point in the system. The two upright rads in the bathrooms are a good 50cm higher but rarely have more than a quick "pfffft" of air if I open the bleed valves. All the radiators get hot from top to bottom (except when the landing one needs bleeding) and the noise stops after a couple of minutes running.

Wondering what could be causing one radiator to fill with air so quickly, and why there could be so much air trapped in one part of the system. I can't see any sign of a leak. Any ideas?

 

[John.g]

OK, can you post a close up photo of the Drayton data label, we will then see, once and for all, what way the 3 ports are positioned.

You said the "TheGrundfos pump arrow on the front is pointing anticlockwise so is pumping up." can you post a photo of this, the arrow is normally on the side of the pump body and points either straight up or straight down. Sometimes, rarely, there may not be a arrow but if you look at the black asterisk I have placed in both photos below, you can determine from the ridge/bulb on the pump body which direction its pumping in as the start of the ridge will be closer to the pump inlet.

Can discuss the excessive air later depending on findings, above.

 

[Basher]

Apologies for butting in - I am interested! The Drayton/Invensys valve seems not to be a mid-position type.

Valve body, Drayton, TA/V4 3/4in BSP - PHC Parts

Valve body, Drayton, TA/V4 3/4in BSP VF3037 in Domestic Heating Controls Drayton

phc.parts

Does the symbol on the side suggest: in 1, out on 2 or 3? (or that's what the plumber thought!?)
Most suppliers are saying it's "obsolete" (apart from the above) and I can't find a data sheet or spec

The actuator below is just 2 position:

DRAYTON TA/M2 ACTUATOR GENUINE NEW RARE OBSOLETE | eBay

<p>DRAYTON TA/M2 ACTUATOR GENUINE NEW RARE OBSOLETE</p><br /><p>GENUINE BRAND NEW IN ORIGINAL BOX </p><br /><p>BOX IS A BIT WORN FROM STORAGE </p><br /><p>THIS ACTUATOR IS ONLY TO BE USED WITH TYPE TA VALVES </p><br /><p>VERY RARE COMPLETELY OBSOLETE ABSOLUTELY EVERYWHERE </p><br /><p>PLEASE...

www.ebay.co.uk

And yes, too much time on my hands on a weekend morning!

 

[John.g]

It mustn't be, as the the normal type is like a T with the pump pumping into the T "bottom" and the CH & HW on top of the T, however, its worked for years apparently but the left hand pipe to the CH has the cold feed teed into it, if it is like the traditional 3 port then the pump is pumping into the CH port A, if CH only selected or both CH&HW then it will work but if HW (port B) only selected then port A will be closed and the pump will be running against a closed valve with no flow to the HW coil or something like that which would surely have been noticed.

 

[John.g]

Apologies for butting in - I am interested! The Drayton/Invensys valve seems not to be a mid-position type.

Valve body, Drayton, TA/V4 3/4in BSP - PHC Parts

Valve body, Drayton, TA/V4 3/4in BSP VF3037 in Domestic Heating Controls Drayton

phc.parts

Does the symbol on the side suggest: in 1, out on 2 or 3? (or that's what the plumber thought!?)
Most suppliers are saying it's "obsolete" (apart from the above) and I can't find a data sheet or spec
View attachment 87531
The actuator below is just 2 position:

DRAYTON TA/M2 ACTUATOR GENUINE NEW RARE OBSOLETE | eBay

<p>DRAYTON TA/M2 ACTUATOR GENUINE NEW RARE OBSOLETE</p><br /><p>GENUINE BRAND NEW IN ORIGINAL BOX </p><br /><p>BOX IS A BIT WORN FROM STORAGE </p><br /><p>THIS ACTUATOR IS ONLY TO BE USED WITH TYPE TA VALVES </p><br /><p>VERY RARE COMPLETELY OBSOLETE ABSOLUTELY EVERYWHERE </p><br /><p>PLEASE...

www.ebay.co.uk

And yes, too much time on my hands on a weekend morning!

Just noticed that 2 position now, you can get a 3 port diverter valve (2 position) or a 3 port (mid position) valve.

 

[Basher]

Just noticed that 2 position now, you can get a 3 port diverter valve (2 position) or a 3 port (mid position) valve.

I'm familiar with 3-port mid position etc etc. Basically I was coming to the conclusion that this early commercial Drayton is a 2 position diverter, supported by the symbol on the side, the fact that the actuator seems to be 2 position, and thus concluding that the basic plumbing (ie the pump position) might be correct for this particular valve?
And I tried to offer some evidence to support the theory, given that the OP hadn't provided pics that could fully identify the valve and actuator.

 

[John.g]

It could well be, the OP will soon hopefully inform if its either CH or HW but not both.