Biggiebig

So i've manage to get some stability since Saturday night. Basically I opened all the zones so all my thermostats are constantly on then using the high UFH temp I warmed up the house to a comfortable 21-23 deg in various rooms and then I crank the temperatures right down but everything is running constantly. Downstairs is running around 30 deg Upstairs is running at the lowest on mixer which is 40 deg All the rooms have been a stable temperature for 2 days with no drops. Now I know that temps have also increased so i've yet to test in sub zero temps but at least now i'm not experiencing low temps. So thank you everyone for the helpful comments Next I will be purchasing Salus auto balancing actuators to have optimum flow rates.

So overall I’ve come to the conclusion that I will have to run at high temps to warm rooms up.

Just checked again the the temps back to 44 out 33 return on most zones. Wonder why I don't get this delta at lower temps, wondering if I need Salus actuators would it make any difference ?

Right got my temp gauge now measurements of my upstairs pipe Strange - It's was showing 44 deg for incoming and around 6-8 deg lower for return so all looks good then mixing temp drops Now outgoing pipes show 34 deg and return shows the same may be 1deg difference in some cases Not sure why the sudden fluctuation Floors are showing 20 deg with the gun and then my cold spare room which barley gets to temp suddenly drops to 16/17 deg

Downstairs not sure why we run at 50 just have done for 10 odd years and kind of use to it we have 100mm celotex boards followed by 80mm concrete and engineered wood and downstairs never had any issues. I will try running at low temp for longer periods and see if it works better downstairs. Also I have changed the setting on the pump for proportional to constant as it was set incorrectly i'll check if that helps. What speed do people recommend remember it's quite a large floor arear

Insulation is pretty good Most of the rear of the house has been rebuilt to modern build reg (last 12 years) The front has External cladding wrapped around and we have double loft insulation. So even though not perfect the insulation isn't terrible. The UFH is on XPS foam boards followed by old wooden floor boards and then insulation between the joist. I have removed lights and speaker from downstairs and no obvious heat escape. When we have a box on the carpet then it does appear to be very warm underneath and under the beds seem warm just the floor doesn't get to Temp.

I’m getting increasingly worried that the ply/carpet have a very low thermal conductivity letting no heat through. As it stands it’s pretty useless as heating and costs a packet to run. I do wonder where all the heat energy is going..

thanks had pump on 1 last night and all flow rates at around 2 with mixer at 40. temps in bedrooms range from 15.5 - 17.5 and have been running all night using 70kwh of gas. so still no real difference I’ve changed the pump speed to 2 now. yeah both outgoing pipes hot out and warm in. I’m getting a IR thermometer today so will report back when I can measure.

Down stairs is a 3-4 hour boost which works well as the concrete heats up and gives us a toasty 20-21 for 24 hours upstairs as temperatures aren’t being reached it pretty much runs 24/7

Yes underlay and carpet the underlay (special for UFH) from memory the combined tog is 2.6

Down stairs is also around 50 but I have a thick slab of concrete so it take a while to come up other wise. i'm currently using around 190 KWH in very cold weather (south west) for a 2300 SQ FT house.

The aluminium foil has been laid on top of the pipe could this be preventing the heat from coming up ?

The coldest bedroom is 14.4 and heating has been on all day floor is cold. could it be heat loss can’t see where as even when you enter the room floor is cold to touch. Could it be the ply/carpet not letting heat up. I just removed a spot light from downstairs and shifted the insulation to the side the floorboard is slightly warm to touch but guess this is expected.

hi, I've had UFH downstairs over 10 years and been please with it. In the summer it was installed upstairs and now rooms are struggling to get to a decent temperature. Here are the details : Property: 1930s semi. Exterior foam installation at the front. Rear and Side comply to recentish building regs having the house renovated within the last 10 years. Loft installation is decent with double layer. Windows double glassed replaced (Rear recently, Front 10 years ago). Boiler: Powerful Valiant Gas Boiler Upstairs UFH System: 6 Zone manifold , installed with auto airvent, pump , and mixing valve, thermostat on incoming , Tado thermostats in each room UFH installation: On existing floorboards > Foam underlay boards > 15mm poly pipe > Aluminium Foil on top > 20mm ply > UFH underlay < wool carpet (2.5 tog) Flow Rate: Set between 2-4 (i've tried varying these but no joy) The bedrooms temp vary from 18 deg (Max) with two bedrooms not exceeding 17 deg and 15 deg in very cold weather. This is in cold weather and temp set to 50 deg. Boiler is set to 60 deg flow. I've tried quite a few things like messing around with flow rates and even flushed the system incase it had air but no joy. My bills are insane atm as i'm keeping the system on 24/7 and boiler/pump is always running as rooms don't get to temp. Not having the ability to not have toasty rooms concerns me and i'm worried there's something fundamentally wrong with the installation e.g plywood too thick or wool carpet trapping the heat. All the bathrooms seem fine as the floor is warm but bedrooms seems to struggle. ATM my only option is to revert to AC heatpump for backup secondary heating.