No flow on small underfloor circuit

[king of pipes]

Mate inherited this had a look this morning for him any obvious faults? ,should work far as I can tell heatmiser programmable stat fitted in the hall way . Kop

 

[ShaunCorbs]

Turning all the orther rads off does it work ?

 

[Scott_D]

No pump?
How does it circulate?

 

[ShaunCorbs]

No pump?
How does it circulate?

system pump/boiler pump

 

[Scott_D]

But the blending valve would stop circulation when water is too hot?

 

[king of pipes]

No didn't seem to system boiler flow and return come off first before rest of the house circuits I can understand their thinking as s plan and controls are in the airing cupboard so easy way to get time and temperature control to under floor loop may just be air locked dosent take much. Kop

 

[Whn1]

Blocked gauze in the blending valve?

 

[king of pipes]

Systems is clean found this online looks like it may need a pump its a valliant system boiler and not getting the water moving through the loop it gets to the mixing valve and back ok just not around the loop . Cheers kop

 

[Last Plumber]

I would say that cannot work!
There is nothing to take return water into mixer valve.
As @scott_d said, as soon as the water is hot going through the TMV, it will fail safe and restrict flow to zero. As it cools down it will open slightly and allow a bit more flow but only until the water temp entering the valve is too hot again.
It is a Heath Robinson attempt at making their own underfloor Heating circuit in my opinion. It needs the correct pump/mixer set up.

 

[king of pipes]

Got a second hand pump will give it a go if all else fails i will get a small pump set sorted . Cheers kop