I have had UFH fitted to an extension approx 50m2. I believe the screed depth is 100-130mm with 100mm kingspan PIR beneath. The system as a whole takes a long time to affect the room temperature, it is set to come on at 6am and by 11am in may have raised the temp by 1-1.5degrees. It is also costing around £4 a day to run (according to a smart meter) and I have seen my utility bills nearly double. I know there are many variables that effect the running costs of UFH but this seems out of control. Any advice as to why it may be costing so much and what I can do to help reduce it. I have a HIVE thermostat with water temp set at 45degrees with the rom temp set at a min of 20.5 going up to 22 at times through the day. Thanks.