UFH not working / Inefficient

[KineticBuser]

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

[JohnMo]

3 hours ago, KineticBuser said:

Everything ive read says that UFH should be set to 1 L/M i presume this is per circuit?

Not sure where you have been reading.

 

You would normally set the flow by loop pipe length. 

 

The flow rate for an underfloor heating (UFH) loop is calculated by dividing the loop length by 40. For example, a loop that is 100 meters long has a flow rate of 2.5 liters per minute (l/min). 

 

You then set the flow to get the dT between flow and return within acceptable limits. Low temp systems are normally between 4 and 6, high temperature 10 degs is better.

 

I would start by setting to 2.5L/min for each loop and see what happens room by room. If the flow will not get to 2.5 l/min then you have air in the system, this will have to be removed.

 

If room ends up too hot reduce the flow a little in that room only.

 

3 hours ago, KineticBuser said:

getting 0.1 degree increase an hour

That's pretty normal depending on floor build up.

 

3 hours ago, KineticBuser said:

water into the manifold was 24c

That is very cool. You will not feel that in the floor.

 

 

[KineticBuser]

Any idea how to increase the water temperature? Nothing i touched seemed to alter that thermostat temp, apart from it running, then as the rooms have warmed the thermostat has increased up - Have Engineered woods floors and some carpets 

The 1 L/M was because im using a heat pump, seemed to be the listed value in a few places

Thoughts on fitting Auto Balancing Actuators so i dont need to bother with the flow meter settings? Worthwhile upgrade? 

 

[ProDave]

Need pictures of what you have, manifolds, pumps, valves etc

 

[KineticBuser]

[JohnMo]

14 minutes ago, KineticBuser said:

The 1 L/M was because im using a heat pump, seemed to be the listed value in a few places

That's just a load of rubbish - ignore. If your loops are less that 40m long it maybe ok anything else bad advise.

[JohnMo]

Looking at the images you have a heat meter. Press the black button until it displays kW. How many kW are you inputting to the floor?

[KineticBuser]

The Grunfos thing - Yeah it doesnt display anything just a load of settings that ive just changed from PP1 to CP1

 

[Temp]

5 hours ago, KineticBuser said:

UFH was working, but one room was always cold, over the summer had some pipes moved and then heating didnt work

 

Think you need to check they were just moved not accidentally swapped?

[KineticBuser]

On 25/11/2024 at 18:36, JohnMo said:

That's just a load of rubbish - ignore. If your loops are less that 40m long it maybe ok anything else bad advise.

Set it back to 1 on grunfos temp as seemed to have gone backwards as getting no heat through, the actuators are warm, but the supply and flow pipes are stone cold and the Pipe thermostat into the Manifold is reading at about 18c

Do you know what the + - valve on the right of the pump is likely to be and controlling is the the mixer or the release valve maybe?.. I have tried turning it fully to + and i can either hear water or air, however turning it back  a few turns and the sound disapears 

[KineticBuser]

This is the system
https://assets.danfoss.com/documents/353645/AQ082486478026en-010501.pdf

[KineticBuser]

I presume it is the mixing valve as per 6.2.1 IHPT 90 controller (45–65 °) and therefore i have set to the fully - position and then turned towards + 5 times to get to 48c which i presume is what i should of done

[Andehh]

As has been said. What's your daily kwh usage?

 

If your floor has been cold for a few days whilst you've been figuring it out, it could talk a couple of days worth of heat to warm it up! If the pipes going into the floor are warm, and the pipes coming out if the floor are cool then the system is working fine and you need to give it more time.

 

If all else fails hire a thermal camera and or use an IR Thermostat to have a look at what's going on.

[KineticBuser]

Ok turned out that i wasnt going mad and i had a temperamental valve thats now been replaced, therefore trying to get the thing setup efficiently if anyone knows the answers to the following?

With district heat do i pay for the water amount? Or the cost of heating the water? If its just the water amount then i guess i want the water as hot as possible?

I have the current water temp set to 50c into the manifold (combo of engineered wood and carpet) presumably i should increase this until my floor temp is 27c?

Should the pipe thermostat be on the flow or return on the manifold? Also i seems to be tripping out at 40c which doesnt make sense as the water going is 50c

Is there any advantage to having the pressure set to 1.5bar rather than 1bar (which is what the other flats seem to be at) even though EON say it should be 1.5

Thanks

 

[ProDave]

5 minutes ago, KineticBuser said:

With district heat do i pay for the water amount? Or the cost of heating the water? If its just the water amount then i guess i want the water as hot as possible?

Ah so you buy hot water from a central source?  that is usually fed into a local calorifier in your property and metered at that point.  The temperature you mix it down to for your UFH would make no difference to the cost you are charged.

[KineticBuser]

1 minute ago, ProDave said:

Ah so you buy hot water from a central source?  that is usually fed into a local calorifier in your property and metered at that point.  The temperature you mix it down to for your UFH would make no difference to the cost you are charged.

 Thanks thats what i thought, so financially im better off having the water as hot as possible under the floor as ive already paid for the cost of heating it

[ProDave]

7 minutes ago, KineticBuser said:

 Thanks thats what i thought, so financially im better off having the water as hot as possible under the floor as ive already paid for the cost of heating it

You don't want it too hot under the floor.   If the UFH temperature is lower that means it draws hot water out of your local calorifier more slowly, so should not affect the cost to you.

[JohnMo]

1 hour ago, KineticBuser said:

so financially im better off having the water as hot as possible

I doubt that, as you have a heat meter so will pay by the kWh.

[KineticBuser]

4 minutes ago, JohnMo said:

I doubt that, as you have a heat meter so will pay by the kWh.

Ok amazing thanks - ill balance it out then to whats sensible.. 

Is there any benefit of the system being at 1.5bar rather than 1bar apart from the operating restrictions of Heat Exchanger etc?