Stoneblade

That's what I thought when they said that. I said I've read in most references to underfloor heating, low and slow. We have laminate throughout the flat. Has a thin foam underlay. Though the floor isn't exactly flat, so may be a gap of a few mm every so often.

@JohnMo I have tried before with leaving the system on for 24hrs, even at a lower temperature, it never seems to increase in temperature in the rooms. I rang nuheat (who designed the system) earlier and they told me the system is designed to have a flow of 50c for the heat loss? lol Im at a loss let alone heat. @Iceverge is working, compressor symbols are displayed on the control panel and heats the water and the manifold is hot. I don't think these units have back up heats, only internal to the water tank when it does the sanitise process. It tends to go on for 10 mins and then turn off for about 5 and then back on. Would this this be classed as fast cycling?

@JohnMo Would making 1 big zone mean getting rid of all the thermostats and just having 1? Or still have the separate ones but if any call for heat they open all zones? @joth No Idea if it has an inverter. I have attached the details of the ASHP below. Ive got one loop in the hall always on now, but guessing this isn't enough? Thanks for the replies.

Hi all, Been a avid reader of the forums for many years, learnt a lot, thanks. But need to ask for some help on our current system. Moved into a top floor flat (in Cornwall) about 2 years ago and for the past 2 winters have had a cold flat! The flat consists of open plan kitchen/lounge, 2 bedrooms, hall and a bathroom (added heated towel rail to help). Each room is zoned. It is powered by a Daiken Altherma 6kw, which is about 11 years old now, with a small hot water storage tank. I also have a MVHR installed due to getting quite a bit of condensation. Have made a few changes this year with adding salus auto balancing actuators and Heatmiser NeoStat to each room. It takes about 6 hours to feel anything through the floor or the air temp to move a degree. It is costing us a bomb to heat this small flat. I have tried weather compensation to save some electric but takes even longer to heat up. I have tried leaving on for a few days without set backs and still struggles. I've found the original design diagram for the system and it states 50c flow temp, does this mean it has to be set at 50c flow temp for it to work correctly?? My ASHP would struggle to get to that. I'm wondering if they have designed to a boiler instead of a ASHP in the original stages? I have attached the original manifold and flow rate diagram, plus the pipe floor plan. I also noticed that the manifold doesn't match real life, i.e. port 1 = bedroom 1, port 2 = bedroom 2, 3 = bathroom, 4+5+6 = Lounge/Living room, 7 = Hallway I am also finding that the auto balancing actuators are a bit hit and miss, and not sure they are compatible with ASHP. Either they are fully open or seen them sometimes fully closed. I have tried contacting Salus who originally sent out a new updated firmware version, but still the same issue. I have also recalibrated on several occasions following the steps given on this forum and the tech support. don't know where else to start, ready to pull my hair out, well the little I have left haha. Any pointers would be gratefully received.