Underfloor heating manifold plumbing

LeoD

Does it make a difference that our manifolds (2) are plumbed backwards - the feed is entering at the top (where it says Out in blue) and the return is exiting at the bottom (where it says In in red)? Every plumber that has looked at it says it doesn't make a difference so I'm wondering why would the manufacturer bother with the labels if it didn't matter? The flow meters never budge from their current position (0) - is that because there is no flow or is it because of the backward plumbing? Our heating is not performing anywhere near what it should be so I'm just wondering does anyone have a different view?

rolion

Don't think is wrong as the water will flow any ways.
It may be that they fitted / started wrong with the main loop...the one carrying the hot water to the underfloor.

I guess that your flow meters are zero because the actuators are not "controlled" / armed by the heating controller ?
Is there a dfference between kitchen and utility VS other zones ... or all zones are cold and zero ?

What is the temperature or the flow and for the retur ?
Can you post photo of the mixing and pumping system,also the controller ?

hatchman

U can adjust the actual flow with the flow meters pop up the orange cover and twist the flow meter u will need you heating on i.e. the pump on. Also make sure the caps on the top manifold are not screwed down stopping the flow in that loop.

K.Flyer

Why are the actuators missing?

LeoD

rolion wrote: »

Don't think is wrong as the water will flow any ways.

That seems to be what everyone says but I was wondering would it make a difference whether you controlled the flow at the start of the loop or at the end? In theory probably not but I have my doubts.

rolion wrote: »

I guess that your flow meters are zero because the actuators are not "controlled" / armed by the heating controller ?

The actuators are controlled by individual thermostats. Right now all the flow meters are opened to full but none of them ever appear to measure any flow rate, even when the heat is on and the floors are warm (in places).

rolion wrote: »

Is there a dfference between kitchen and utility VS other zones ... or all zones are cold and zero ?

In the manifold shown here, all loops are working, or at least giving off some heat.

rolion wrote: »

What is the temperature or the flow and for the retur ?

About 25/19.

rolion wrote: »

Can you post photo of the mixing and pumping system,also the controller ?

Everything is contained within one unit - Ecodan Monobloc Packaged Cylinder

hatchman wrote: »

U can adjust the actual flow with the flow meters pop up the orange cover and twist the flow meter u will need you heating on i.e. the pump on. Also make sure the caps on the top manifold are not screwed down stopping the flow in that loop.

I've adjusted them all (opened them all fully) but nothing visually changes. I presume there is some flow rate happening as the floors do warm up slightly.

K.Flyer wrote: »

Why are the actuators missing?

Actually that's a good point! I thought it was because one thermostat was controlling multiple rooms but that doesn't make sense now. Will have to investidate further.

froshtyv

It does matter which way the manifold is plumbed.
As you said yourself why would the manufacture bother labelling it if it didn't matter.

The reason it matters is down to the flow meters.

Some manufactures require the flow meter indicator to be pulled down when there is flow circulating.
In this scenario the flow pipe needs to go on the manifold with the flow meters.

Other manufactures require the flow meter indicator to be pushed up. So the return from the underfloor heating loop pushes the indicator up.
So the return pipe needs to go on the manifold with the flow meters.

From looking at your manifold, i would imagine that the red indicator sits at the top of the flow meter where it reads 0?
This needs to be fitted to the flow pipe. As the water enters the manifold it pulls down the flow meter as it circulates through the underfloor heating loop.

Water John

Those without actuators are open circuit.
Flow rate on each flow meter should be about 1.5l/min.
It's plumbed correctly for a low heat source eg Heatpump
If there was a mixer added on to use a high heat source eg Oil burner it would be plumbed in reverse.The hot water coming in the top and the impeller pump pushing the mixed water out via the flow meters.

LeoD

froshtyv wrote: »

It does matter which way the manifold is plumbed.
As you said yourself why would the manufacture bother labelling it if it didn't matter.

The reason it matters is down to the flow meters.

Some manufactures require the flow meter indicator to be pulled down when there is flow circulating.
In this scenario the flow pipe needs to go on the manifold with the flow meters.

You are right. We've just flushed out all the loops by connecting our supply to the flow (red) manifold and hey presto, the meters are moving and registering the flow rate. When we reverse the connections the flow still exists but the meter doesn't work. Got the same reply from the manufacturer about 10 minutes ago also.

Thanks to everyone who replied. Will update thread if and when we get the system resolved.

LeoD

K.Flyer wrote: »

Why are the actuators missing?

The loops with actuators are controlled by individual room thermostats. The loops without actuators are controlled by the temperature controller on the cylinder unit.

LeoD

OK, the system is now working a lot better but still not at the level I would expect. The flow rate measured by the flow rate meters is very low - less than 0.5l/min but it's hard to be exact as the indicators hardly move from zero when all loops are open and 'balanced'. I have gone through every loop individually to check the meters and flow rates and when I do this the indicators do move and I get up to 5l/min flow. There is no air in the system either. When I close one manifold, I can get flows from 0.5l/min to 1.0l/min on the other manifold so to me it just looks like a lack of pumping power. We have fitted an auxiliary pump next to the water tank which does help slightly but how much power do we need? Would we be better off putting the auxiliary pump nearer one of the manifolds to help with flow? I don't have the exact length of underfloor piping but at a guess I would say we have around 1500m.

Water John

Yeah, you're at the limit of pipe length. Normally designed to 14 loops of 100m max each.
The impeller pump may have 3 settings. Your looking for a flow of 1.5 on each flow meter.
Its in my memory and could be wrong, but the resistance of the flow meter itself was significant. If the loops are similar length, you could remove the flow meters and cap the points. Their main use is balancing short and long runs in different loops.

They are male threaded caps, around half inch, I think.

rolion

LeoD wrote: »

We have fitted an auxiliary pump next to the water tank which does help slightly but how much power do we need? Would we be better off putting the auxiliary pump nearer one of the manifolds to help with flow?
I don't have the exact length of underfloor piping but at a guess I would say we have around 1500m.

This is my 2008 setup,with a mixing thermo valve AND a pump dedicated to ufh !

gifted

rolion wrote: »

This is my 2008 setup,with a mixing thermo valve AND a pump dedicated to ufh !

Jeez...you gotta love the beautiful electrical containment lol lol
Our sparky cousins get away with murder lol lol

rolion

gifted wrote: »

Jeez...you gotta love the beautiful electrical containment lol lol
Our sparky cousins get away with murder lol lol

I know,all done DIY !
In the process of upgrading to this one here:




AND,controled by the EvoHome brain here:

LeoD

Latest update - don't think I had mentioned before but we had an issue with pressure dropping also but no visible signs of a leak anywhere. Turned out we did indeed have a leak but fortunately is was outside close to the heat pump itself. An elbow joint simply not tightened by the original installer. Relief all round as the pressure hasn't dropped in nearly 3 weeks now so we're assuming that's that issue sorted. My only issue now is trying to up the flow rate. I did get details of the heating plan. Manifold 1 is about 4m from the pump and manifold 2 is about 12-14m away from the pump. The loops off manifold 1 perform significantly better. We live in a bungalow.


Manifold 1

1. 30m
2. 100m
3. 85m
4. 91m
5. 72m
6. 44m
7. 48m
8. 40m
9. 45m

Total 555m


Manifold 2

1. 100m
2. 46m
3. 70m
4. 53m
5. 30m
6. 100m
7. 21m
8. 94m
9. 95m
10. 35m

Total 644m

GRAND TOTAL 1199m

Does it make a difference where the pumps are located or would putting them on the manifolds work better?

Water John

I presume you don't have a split valve for the supply to each manifold. That would be the first place to divert supply and bias more in favour of manifold 2.
Is manifold 2 upstairs? Then you have a head pressure to overcome. most pumps have 3 settings and you could up the manifold two.

You could trottle back the flow meters on manifold one, another option.

The feed to manifold one in the pic has a valve. Turn this a little and cut supply a bit and see does it help manifold two.
Just ideas to play around with.