UFH - zone not heating up. No flow...

[newhouse87]

6 hours ago, JohnMo said:

 

 

Understand if the pump cannot supply enough flow to manage the flow requirements it will supply the lowest head loss loops and ignore the high loss loops.  Which maybe the case here.

 

But a conflicting statement is

And

 

Also if all flows show 2.5 l/min, would suggest zero commissioning has taken place and the flow are not balanced.

 

Big pump or 2 maybe needed for 16 x 2.5l/min

I didnt make them 2 statements. Ill ring daikin in the morning and see what they say about circulation pump. When i have all loops on im getting same flow as i would with just 1 on. Would that not suggest its pumping fine. figured out sitting room stat was wired to wrong loops this mornring, was able to scrape off paint to see plumbers writing so sitting room sorted now.

Edited March 5, 2023 by newhouse87

[Jimmyjazz]

Often pumps are not required on underfloor manifolds. When mixing valves are added you often need to add a pump to overcome the resistance but as you say if you are getting flow in the other circuits there is most likely an issue on this circuit. When you tried to flush the loop before, did you put the hose on the flow or return? there are non return valves on the manifold so if you are attaching the hose on the return manifold bar you won' push it through. You will blow the hose off as you have done.

I would say it is highly unlikely to be a pump issue. Can you not get someone who knows what they are doing to take a look?

[newhouse87]

 i hijacked this thread man. i had slightly diff issue to original poster. Have bungalow aswell so should make it easier for integrated pump.

Edited March 5, 2023 by newhouse87

[Nickfromwales]

12 hours ago, Jimmyjazz said:

there are non return valves on the manifold so if you are attaching the hose on the return manifold bar you won' push it through.

I've never seen a manifold with non return valves. Do you have them on yours?

Not had one on any manifold I've ever fitted, over the last couple of decades, just flow gauges and the attenuators where the actuators connect to switch each loop on / off. 

[dpmiller]

flow gauges act as a coarse NRV do they not?

[PeterW]

8 minutes ago, dpmiller said:

flow gauges act as a coarse NRV do they not?

Yes but you can push past them and they shouldn’t be used as such

 

@newhouse87 the paperwork is what you need if / when you have a warranty claim or when you need to have the unit serviced to keep within the manufacturers warranty.

 

I would start with getting the controls correct and then look at the pump but tbh I don’t think you’ve got an optimal system there

[Nickfromwales]

2 hours ago, dpmiller said:

flow gauges act as a coarse NRV do they not?

With cold mains they pass. But yes, direction of flow should be observed to not damage the flow gauges..

Poster stated they have non return valves, which they don't.

[Jimmyjazz]

On 06/03/2023 at 10:07, Nickfromwales said:

With cold mains they pass. But yes, direction of flow should be observed to not damage the flow gauges..

Poster stated they have non return valves, which they don't.

I may have used the wrong terminology trying to simplify the situation. if you put a hose pipe on the return bar of a manifold you should not get any flow back through to the flow manifold. Give it a try.  They don't pass. They don't  however have what you would call a traditional check valve

[Nickfromwales]

2 hours ago, Jimmyjazz said:

Give it a try

 I have, once or twice  

[Dave Jones]

some heat pump cylinders do not need a separate ufh manifold pump, seen a couple installed.