Jump to content

UFH not working / Inefficient


Recommended Posts

Trying to understand what is happening with my UFH and also if my logic is correct.

3 bed flat, Lounge and 2 bedroom upstairs 700 Sqft - 1 bedroom downstairs 300 sqft (guess)
UFH was working, but one room was always cold, over the summer had some pipes moved and then heating didnt work


Centralised Hot Water system
The heat pump is all controlled by Eon (but taken cover off)
The pump is grundfos alpha2 l 15-40 
The UFH is polypipe

What i did 
Refilled system
Depressure Manifold 
Took off Flow Meter and made sure working 
For each circuit (4) put the flow meter to 1 L/M as when higher the room didnt get hotter

 

State
I now have the flat warm finally but its taken days, and i was getting 0.1 degree increase an hour in the rooms (but this may have been from zero as no water in system before i started)
The water coming in from the flat is very hot on the pipe, the water into the manifold was 24c but seems to increase as the rooms get hotter (but floors dont feel warm)
The Grunfos system when you turn on defaults to 1 but manual says it should be on setting 3 for UFH at which point the flow meters jump, however in the 10yrs in the flat ive never changed it

Questions
Have i got an airlock, the water isnt hot enough under the floor or a flow rate issue?
Is the Grundfos on the right setting? If i changed this then im guessing more flow = most cost and if the water isnt hot enough for the flow im just pushing cold water through?
Everything ive read says that UFH should be set to 1 L/M i presume this is per circuit?, i dont really see how i can accurately adjust this between 0 and 1 on a float to balance the system.
What is the black RAVK valve doing? 
There is a adjuster to right of the Grundos that seems to do nothing
There is a valve near the Thermostat that has the temp of the water going into the thermostat - not sure what that does either.

Also is it possible the system was just so cold its taken this long to get heat through it all? Obviously want the house to be warm but would like to not bankrupt myself in the process

Thanks for the advice

20241124_162444475_iOS.jpg

20241125_114219528_iOS.jpg

20241125_114212198_iOS.jpg

20241125_114133474_iOS.jpg

20241125_114129767_iOS.jpg

20241125_114126236_iOS.jpg

Link to comment
Share on other sites

Christ that looks like a lot of bits to go wrong. I can only comment on flow rates. It’s not one number suits all I’m afraid. You can work it out for yourself using LoopCad available freely on the internet. It’s a combination of loop length, pipe diameter, flow temp and heat loss. You should know the first 3, the last one you can work out from Jeremy’s infamous spreadsheet on here

Link to comment
Share on other sites

I guess it’s possible you don’t know the first 1 if you didn’t lay it. Some pipe has markings on it per meter. You can do the diff to work out the length. Else, grab a thermal camera and check where the pipe runs

Link to comment
Share on other sites

On 25/11/2024 at 13:38, KineticBuser said:

Trying to understand what is happening with my UFH and also if my logic is correct.

3 bed flat, Lounge and 2 bedroom upstairs 700 Sqft - 1 bedroom downstairs 300 sqft (guess)
UFH was working, but one room was always cold, over the summer had some pipes moved and then heating didnt work


Centralised Hot Water system
The heat pump is all controlled by Eon (but taken cover off)
The pump is grundfos alpha2 l 15-40 
The UFH is polypipe

What i did 
Refilled system
Depressure Manifold 
Took off Flow Meter and made sure working 
For each circuit (4) put the flow meter to 1 L/M as when higher the room didnt get hotter

 

State
I now have the flat warm finally but its taken days, and i was getting 0.1 degree increase an hour in the rooms (but this may have been from zero as no water in system before i started)
The water coming in from the flat is very hot on the pipe, the water into the manifold was 24c but seems to increase as the rooms get hotter (but floors dont feel warm)
The Grunfos system when you turn on defaults to 1 but manual says it should be on setting 3 for UFH at which point the flow meters jump, however in the 10yrs in the flat ive never changed it

Questions
Have i got an airlock, the water isnt hot enough under the floor or a flow rate issue?
Is the Grundfos on the right setting? If i changed this then im guessing more flow = most cost and if the water isnt hot enough for the flow im just pushing cold water through?
Everything ive read says that UFH should be set to 1 L/M i presume this is per circuit?, i dont really see how i can accurately adjust this between 0 and 1 on a float to balance the system.
What is the black RAVK valve doing? 
There is a adjuster to right of the Grundos that seems to do nothing
There is a valve near the Thermostat that has the temp of the water going into the thermostat - not sure what that does either.

Also is it possible the system was just so cold its taken this long to get heat through it all? Obviously want the house to be warm but would like to not bankrupt myself in the process

Thanks for the advice

20241124_162444475_iOS.jpg

20241125_114219528_iOS.jpg

20241125_114212198_iOS.jpg

20241125_114133474_iOS.jpg

20241125_114129767_iOS.jpg

20241125_114126236_iOS.jpg

 

I thought I replied to this, anyway,

That pump setting of proportional pressure PP1 is not suitable, apart from being far too low, for UFH, suggest setting to constant pressure CP2, (LED on far right, no4), this is a constant pressure of 3.0M, then set your flowmwters to 2 to 2.5 LPM and see how it goes.

Link to comment
Share on other sites

Thanks @John Carroll I thought you had as well (weird) and your advice and reading manuals i understand the flow control and pumps however whilst i was working that out i seem to have gone backwards, when trying to work out how it all worked i took off ATP Pipe Thermostat off the Manifold not realising what it did.

The ATP Pipe Thermostat is back on the flow meter Manifold and set to 60c 

Not sure if thats caused the issue but the Heat Exchanger for the UFH is stone cold, Whilst the Heat Exchanger for the water is hot and working
The pipe out of the UFH Heat Exchanger into the Manifold is also cold and reading 15c
The pipe that feeds into the Differential Pressure Controller is hot (and then its difficult to tell due to thicker pipes but by time its gone through the RAVK Controller and the Thermo Activator its cold

The Thermo Activator i think is ok, it says its naturally closed, and when i shut down power the black middle bit of plastic goes down, and when i power back up and the polypipe controller kicks in it gradually protrudes out

Picture below, but i cant work out what to do next

This is the system



Thanks again

Heat.jpeg

Edited by KineticBuser
Link to comment
Share on other sites

You have written the steps you did in the first post. The main thing you have done 

 

On 25/11/2024 at 13:38, KineticBuser said:

over the summer had some pipes moved and then heating didnt work

 

 

On 25/11/2024 at 13:38, KineticBuser said:

Refilled system
Depressure Manifold 
Took off Flow Meter and made sure working 
For each circuit (4) put the flow meter to 1 L/M as when higher the room didnt get hotter

I assume you took a note of the setting before you started fiddling?  Confirm.

 

Can you set them back to where they started?

 

Can you set the flow rates to each loop to 2.5L/min?

 

Is one or more loops achieving flow? Are all or none achieving flow?

 

Those not achieving flow are likely to have air trapped and they need bleeding.

 

While doing this monitor the kW on the heat meter (Sonometer) and report.  The heat meter will also tell you flow rate, and temperatures, just press the black button and it will scroll they different readings 

Link to comment
Share on other sites

12 hours ago, KineticBuser said:

0.008 m over h

0.059 k W

This (above) would indicate you have no flow and almost no heat. Are these reading still true when flowing?

 

2 hours ago, KineticBuser said:

All showing at 2m /l as thermostats on in all rooms and actuators are open

 

Link to comment
Share on other sites

I would suspect you have air either in the heat exchanger loop or a valve closed to stop water circulation through the heat exchanger part of the system. 0.027m³/h is only 0.45l/min.

 

So pump is pumping water around the UFH loops, but nothing is making its way to the heat exchanger.

 

Using the drawing from the manual and make sure all valves are open. Then if all is ok you will need the manual to understand how to get air out the system.

Link to comment
Share on other sites

On 02/12/2024 at 22:22, KineticBuser said:

Thanks @John Carroll I thought you had as well (weird) and your advice and reading manuals i understand the flow control and pumps however whilst i was working that out i seem to have gone backwards, when trying to work out how it all worked i took off ATP Pipe Thermostat off the Manifold not realising what it did.

The ATP Pipe Thermostat is back on the flow meter Manifold and set to 60c 

Not sure if thats caused the issue but the Heat Exchanger for the UFH is stone cold, Whilst the Heat Exchanger for the water is hot and working
The pipe out of the UFH Heat Exchanger into the Manifold is also cold and reading 15c
The pipe that feeds into the Differential Pressure Controller is hot (and then its difficult to tell due to thicker pipes but by time its gone through the RAVK Controller and the Thermo Activator its cold

The Thermo Activator i think is ok, it says its naturally closed, and when i shut down power the black middle bit of plastic goes down, and when i power back up and the polypipe controller kicks in it gradually protrudes out

Picture below, but i cant work out what to do next

This is the system



Thanks again

Heat.jpeg

Is that actuator being energised? Is it actually opening?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...