Underfloor heating flow direction incorrect?

[HighTower]

Hi All,

We're been living in a new build property for the past 2 years without any obvious heating issues. We've an underfloor heating system that's split across 4 rooms, and is driven by a Daikin ASHP.

I've occasionally had to take the actuators off in order to release stuck pins after periods of minimal heating activity, but always noticed that the flow valves show 0 flow when the system is on or off. When pressing the zone pin down, the associated flow meter bounces and a knocking sound is heard through the pipe.

After watching a few videos online, I wondered if the system had been connected up around the wrong way, but couldn't find confirmation anywhere. When the system is running, if I manually depress one of the pins for about 30 seconds and take temperature readings off the pipes, I see 37 degrees beneath the actuator at the bottom of the manifold .At the top, I see 26 degrees under the flow indicator for the same loop (see attached photos).

 

Am I correct in thinking the flow into the manifold is around the wrong way? If so, apart from not giving an accurate flow indication, does this cause any problems? The house is certainly warm enough through colder periods (22-23 degrees) but I wondered if the system would be as efficient as possible in this configuration?

Any advice gratefully appreciated.

Thanks,
Ben

[ProDave]

A better test would be, when you turn the system on from cold, which of the copper pipes on the left heats up first, the top one or the bottom one?

 

[HighTower]

HI Dave, thanks - I've just done this test as well. To the touch, the bottom pipe is certainly getting warmer first. I was also able to confirm this with the infrared thermometer as seen in the images below show (larger number in the middle is the live figure being recorded). It would seem to confirm that this is the wrong way around ? So the follow on question then remains in that does this cause any issues? Do the flow indicators and lower pins have any issues with incorrect flow direction?

Edited February 2, 2022 by HighTower

[Temp]

Photos in here and your comments suggest its the wrong way around..

 

https://www.beneathheat.co.uk/uploads/1518187003_Beneathheat Installation Guide 2017 Proof.pdf

 

I doubt it will affect the efficiency of the system but it might affect the life of the loop actuators and noise if any.

[JohnMo]

Shouldn't have an undue affect on anything, but the flow meters will not read correctly, as you have noted.  Not sure how they balanced the system, or if they did?  May be worth fixing to allow correct balancing.

 

If you are changing the pipes around, install isolation valves on the hot and cold pipes to make any future maintenance easier.

 

[HighTower]

Thanks both, appreciate the responses. I'll contact the plumber and company that commissioned the system and see if one of them can resolve the pipe connections to the manifold. I'll also supply the isolation valves as John suggests for and forward going maintenance.

 

The flow valves if anything would provide a big help in showing when a pin is stuck too, rather than relying on "does this floor zone feel warmer or cooler than I'd expect right now".