UFH - Is this Installed Correctly?

[Alison10]

Hi - please help me. I think our UFH is installed incorrectly. Please see pictures (if anyone needs more images I can take them). UFH-Full-View-Labelled - https://ibb.co/3C0MsKD

The problems we have are. The heating takes FOREVER to heat the rooms. The circulation pump is running all the time - even when the UFH is not required. This is both noisy and costly.

The heating for my house is in 3 zones

• Zone 1 house downstairs - radiators (with TRVs)
• Zone 2 house upstairs - radiators (with TRVs)
• Zone 3 extension - underfloor heating (with room stats in all rooms)

Controls:

1. A room stat in the hallway controls the temperatures of zones 1 and 2
2. A timer in the utility controls the on/off for all 3 zones.

There are many things I don't understand about all this:

1. Is the system installed correctly? I've looked at many diagrams that seem to have the pump positioned between the flow and return - not just on the flow pipe.
2. Why do we have another room stat in the UFH room - it needs to be set really high, just to get the heating working? Shouldn't the control on the overall on/off just be from the main heating timing near the boiler?
3. If some sort of control (like the room stat in the UFH room) is required - couldn't it be a simple timer to control when the UFH goes on/off?
4. Why is the pump running ALL the time?

I'm at a loss. Please help, it would be very much appreciated.


Thanks

 

[exedon2]

You really should be addressing you concerns about your underfloor with your installer.
You don't operate underfloor on a 'on off basis' you typically need thermostats that let you select a backset temperature,
The backset would typically be a maximum of 4°C below desired room temperature.
Some clearer pictures taken further back of your manifold/pump/blender would be useful plus pictures of any other zone valves boiler pipework etc.

 

[Alison10]

You really should be addressing you concerns about your underfloor with your installer.
You don't operate underfloor on a 'on off basis' you typically need thermostats that let you select a backset temperature,
The backset would typically be a maximum of 4°C below desired room temperature.
Some clearer pictures taken further back of your manifold/pump/blender would be useful plus pictures of any other zone valves boiler pipework etc.

Hi
The installer has admitted he's not that good with UFH - hence asking on here.
The on/off comment is meant to refer to the overall on/off of the UFH - i.e. when the zone 3 valve from the boiler (not shown in picture) opens to allow the extension to be heated - eg open at 5pm to close at 11pm. This is not the zone valve shown on the flow pipe in the picture.
Regarding pictures - there is nothing else to show in the room with the manifold in.
I'm not sure what 'backset temperature' means.

 

[exedon2]

So to be clear your only allowing heat into your underfloor between 5 in afternoon and 11 in evening?

 

[Alison10]

So to be clear your only allowing heat into your underfloor between 5 in afternoon and 11 in evening?

Hi
Yes. The zone valve to zone 3 (Ufh) opens at 5pm and closes at 11pm. The operation of the ufh is controlled by everything in the picture after that (with the addition of the ufh room stats).

 

[exedon2]

I'm not surprised your underfloor struggles to warm rooms.
To be clear your underfloor should be switched on 24 hrs a day .
You set it to desired temperature then reduce it by maximum of 4°C when room not in use .
The lower temperature is the backset temperature.
Your room thermostats should be capable of doing that.

 

[Alison10]

I'm not surprised your underfloor struggles to warm rooms.
To be clear your underfloor should be switched on 24 hrs a day .
You set it to desired temperature then reduce it by maximum of 4°C when room not in use .
The lower temperature is the backset temperature.
Your room thermostats should be capable of doing that.

Thanks. We will need to change our room stats to digital to facilitate that - we’d presently need to go round each room and turn them down manually each day.
Nevertheless can you please comment on the position of the pump in our setup?

 

[exedon2]

As you have already identified what you have is not a typical set up.
Pump and blending valve normaly being a interagal part of manifold.
Your probably going to need someone eye's on to see it up and running.
The fact your installer fitted normal room thermostats is not a good indication.
Was the system designed/specified by the company who made the manifold/ blender ect?

 

[Timmy D]

I haven’t looked at pictures but each underfloor zone/room needs a programmable room stat.