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UFH not working / Inefficient


KineticBuser

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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

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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.

 

 

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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? 

 

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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.

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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?

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