no. of days required for underfloor system to heat a newly constructed residence

How long does it take for the underfloor heating/heat pump to heat a house of 340m squared at initial start up? Set point is at 41c.

hi iris-typically it would be warm within a day, on a new building,as long as your water flow rates are correct and your secondary pump is running- and vented

Hi steve... water circulation is fine and heat pump is working without stopping. Water temprature inside pipes went from 10 degrees ro 15 degrees in 3 days. There is a lot of moisture under the floor and in walls....they say it takes long time to feel difference in the floor and for water to dry. We dont have wood floor...we have ceramic floor..underneath is cement...if it makes difference.

just moniter the flow ,return temp each day, was there any insulation under the underfloor heating pipework or is it run directly on the base slab?

Its insulated... 10 cms of foam concrete around the pipes.

Return temprature slowly rising 1-2 degrees each day...

The floor should be heated slowly over time otherwise the floor structure can be damaged.

Ok. Well noted. But is this normal? But how many days will it take to feel the difference? A month?

To dry out a 65mm screed naturally could take up to four weeks. Your installer should have given a schedule of how to heat and dry out the floor safely.

Usually with a hp on ufh it will be up to temp within 2 days. Sounds like your heating installation is not right somewhere.

the water inside the big tank is very hot ...and so is the domestic water. the return temperature from the underfloor pipes is slowly rising ... but they say that we should vent the underfloor pipes. this could be the reason why the temperature is rising slowly.

Don't you have auto air vents on the floor loops? Air in the system can be a big problem. Is each loop roughly the same supply/return temp?

Also, why is foam concrete being used as a screed. We don't use the stuff here for that purpose so I am curious as I figured it would not be a good heat conductor AROUND the pipes.

we have at each floor air vents...I guess that the bleeding has to be done manually. both floors are very similar in temperature...both are at 20 degrees. The foam concrete was used based on a study the company did... and it came with the design. I am a home owner ... so not so familiar with all these technical issues. but what do you think? the splits (that are also part of the system and connected to the heat pump) are working fine, they have reached temperature up to 20 degrees as well.