UFH mixing valve not restricting heat to floor

[ShaunCorbs]

it's a bit deceptive but it's within the Gas Safe general requirements and also the manufacturer specific requirements for distance from wall, below opening window and from roof line and roof windows, this was installed by a gas safe engineer too.

What boiler is it ?

 

[Dtwone]

potterton suprima 60 non condensing

 

[ShaunCorbs]

So it's a min of 1m away from the window/wall?

 

[Dtwone]

So it's a min of 1m away from the window/wall?

yeah, 3 maybe 4 roof tile lengths and its a very low pitch 12.5 degree roof so not much length of tile lost in the incline, fitter was not initially sure so actually called Gas Safe to get his interpretation of the diagrams confirmed, it's close to max length of that flue allowed on that boiler with the elbows included but it actually ran better emissions when tested than the original short straight flue did - go figure that?

 

[ShaunCorbs]

I would say it's too close

 

[Dtwone]

I would say it's too close

I'm not questionning the the requirements but it's actually further away from opening windows (both horizontally and vertically) than the old horizontal flue was when the house was newly built, silly house layout with the flue going out of the back wall rather than a side alley.

 

[Dtwone]

well, as a follow up to my call today RWC technical have replied via email and OK'd my install from my description and photos, their advice is to try restricting the zone actuators and then get a new valve body so hopefully I'll get to the bottom of this soon.
Thanks again for all your suggestions, I'll let you know the outcome.

 

[Ric2013]

Thanks again for all your suggestions, I'll let you know the outcome.

I for one will be interested to hear back from you.

 

[Dtwone]

I for one will be interested to hear back from you.

Well its not an over specced pump, with both actuators almost shut off it shot up from 17 degrees to 65 on the manifold input within 10 minutes new mixing valve it is then, you never know perhaps I dropped an olive into it?

 

[Dtwone]

Well I think I've sussed it, I removed the valve to watch the stat react to hot water from the side connection, the stat didn't move at all so I removed the control tap and then the stat and Spring, I then reassembled with no spring and repeated. Still no movement of the stat, and then I realised the stat didn't recess further than flush with the tap base which means no return flow can mix into the inlet through the stat to the pump.
Basically the drilling in the valve body the stat recesses into isn't machined far enough to allow the stat to open!
This also explains why when I wound the tap into the minimum position, if not when it was factory assembled, the stat pin was crushed into the wax body so it appeared damaged when I compared it to a new one.
Pictures uploaded show how the stat plastic surround is flush with the brass body of the tap face when the tap is screwed in, I'll mail the info and pics to RWC but I'm pretty sure it's a manufacturing defect, typical when this is the first time I've used or seen one.