SamKeen

That sounds like a good idea aswell. Cheers mate I’ll order some tonight

Cheers guys

It’s certainly worth a try. I’ll swap the connections for 22mm. It certainly won’t harm. Cheers mate

Feed and return are plumbed to the right ports (H & C). Feed and return are 22mm but they reduce to 15 just as they enter the manifold. I have turned down the mixer to 45 degrees and the flow increases to a suitable level. The rooms are warming up now but the floor itself isn’t warm to touch. Im worked that when I add the floor tiles etc, the system won’t be hot enough… any thoughts?

So I set the red plastic markers on the flow meters to where the internal red indicator needs to get to, and although I can get the right flow on circuits 1,2, 6 and 8, the other circuits are not getting enough. Therefore I’m guessing a higher spec pump is needed? Any other thoughts?

I’ll keep you posted 👍

I think I have made a simple error. I assumed that the pump would be more than sufficient to run all circuits at max flow rate of 5l/m and it would be a case of turning them down… to get to the design flow temps. I now understand that’s not a possibility - at least not with my pump. I have just found some old notes of the circuit lengths and they are not as long as I thought and so the flow rates required are massively reduced on the smaller circuits. Utility - 50m = 1.25l/m En suit - 23m = 0.5l/m Old basement zone 1 - 98m = 2.5l/m Extension zone 2 - 72m = 1.8l/m Extension zone 3 - 63m = 1.6l/m Bedroom zone 1 - 74 = 1.85l/m Bedroom zone 2 - 54 = 1.35l/m Hallway - 32m = 0.8l/m so I think… if I correctly set each zone individually… then I should be able to achieve the 2.5l/m required on the largest circuit. am I on the right track?

Thanks for the reply. Not sure what you mean by commissioned. There were no air bubbles when I primed the system (cold) before the screed was laid. Then I ran the pluming to the manifold and had a plumber put in the 2 valves. Next to the boiler it’s self so the UFH could work without the rest of the house. The flow rates should be around 2.5l/m on the larger circuits. All the flow meters are 100% open. If I close a few of them I can increase the flow on the others. But when they are all open the flow reads about 0.25l/m on each circuit. which indicates lack of pressure? do you mind me asking how many loops you have (total approx length) and what pump you have? cheers guys.

When running the pump is set to the fastest setting (3) not sure what speed that equates to….

Good morning everyone. I have a problem and I’m hoping someone has the experience needed to suggest a cause & solution. New UFH system installed in our extension. It is running off the house combi boiler (baxi 105he). 8 port manifold with actuators. 5 circuits are approx 100m 3 circuits 70m I have 2x 2 port actuators controlling the feed from the boiler - 1 to the old house radiators, 1 to the UFH manifold. The system is working as it should except the flow rates on the circuits are barely registering 0. As such it is taking forever to warm up the rooms. if I close a couple of the circuits, I can increase flow rate on the others, but if they are all open (which is what I need) the flow rates drop to pretty much 0. Is it that my UFH pump isn’t up to the job? See image: fyi - boiler is on 2nd floor (2 floors above the ufh circuits and manifold)