marshian

Does the water circulate thro the HW coil in reverse too?? Easy to check if TRV bodies are bi-directional they have a double headed arrow on them

Anyway system now drained down (again........) I'm ready whenever he finishes his current job Might turn off the water and replace an iffy isolation valve (been on the list for a while)

Sounds like that would screw with your head!!!

Viessmann curves below

I've just looked at the curves for the boiler at 0.2 slope Outside temps and boiler flow temps is in the table below Outside / Flow temp 20 - 20 15 - 22 10 - 23 5 - 24 0 - 25 -5 - 26 Mighty impressive - I'd have to rebuild the house to achieve that - I think I'll be doing really well to get down to 1.0

What's your heat loss at -2?

I have thermostatic mixer controls for both showers in the house - they are quite happy down to 40 deg supply temp on hot side. They only get a little fussy when the HW temp is below 38 deg C They are nothing special - both purchased on line (think soak for one and victoria plum for the other)

Update time Friday afternoon the gas engineer is making another visit - hopefully we will have the system running as it should by the end of the day........... FLW!!!

As I had to have the floor up in the room above the kitchen (where boiler is on an external wall) to run a 3 core cable from Circ pump in the airing cupboard (centre of the house) I looked at the flow and return pipes and decided now was the time to break up the twins so to speak (roughly 2 x 4m of 22 mm copper pipework run bang along side each other (with the traditional nails bent over to hold them in place) New pipework is far enough apart to allow 19mm of insulation around them - annoyingly I don't have enough spare 22mm lagging so that'll need to get ordered asap - just waiting on the gas engineer to come and connect up the pump to boiler wire. Still waiting on a resolution for the HWD/Weather comp situation so running it manually as temps start to get colder. I am absolutely amazed at how stable the flow temps are at 30 Deg and the length of the burns at very low boiler output. SWIMBO is less inclined to comment about the "cold rads" if the house is a comfortable temperature Bodes well for for my estimations that 1.4 slope would probably be a bit high but if I adopted a 24/7 approach I could go as low as 0.8 - but I think we will end up with 1.0 to 1.2 bearing in mind we heat intermittently as the house insulation overall isn't good enough yet. Hopefully the process can move forward again soon - I am mildly miffed that I'm still having to manually change boiler temps for HW and CH but I feel it's moving in the right direction

FF = Ferguson Formula - A 4 wheel drive system that was applied to quite a few marques back in the day (Jenson and Opel) I've got more knowledge on the Opel side (as they are what float my boat) that and the fact a Jenson is out of my budget

I use sonoff (TH100 from memory) - mains powered - can do temp and humdity with one type of sensor or just temp with another type power consumption is very low can use an app on my phone to see temps/humidity from anywhere over wifi or 4G Logs data hourly and keeps up to 12 mths data

About 30 mins max for me and I have 13 rads If it's taking you longer then you are either trying to get a specific temp drop across each rad or you are trying to achieve a perfection that will change every time a TRV calls for heat or turns of the flow to a rad and that's a waste of time

On the run time - it's basically set to when we aren't home or are asleep Power consumption is 9W when running so from memory I must have set it on either 3 or maybe 4 out of the 6 settings - It's been a long time since I changed the speed Claimed air volume on each of the power settings is Setting Litres/sec Litres/min Litres/Hr Hrs for 1 AC 1 10 600 36000 8.08 2 20 1200 72000 4.04 3 30 1800 108000 2.69 4 40 2400 144000 2.02 5 50 3000 180000 1.62 6 60 3600 216000 1.35 The Hrs for 1 AC (OK I know it's not going to drive all the air out there is going to be some mixing) are what I calculated based on volume of the house.

Very useful thank you - I know for my Sonoff Temp sensors I can change the offset value in the app - I've had a look in the app and I can change humidity offset too so looks like a calibration is on the cards for this weekend

Ahh be interesting to know how to do that for the Sonoff units I have - 6 % difference is significant

Great data I was worried about mine (lounge) being in the high 50's to low 60's......... No trickle vents and very little air ingress (due to insulating under the floor) and Patio doors are rarely opened (due to spiders apparently) PIV unit runs 12.5/24 hrs and certainly lowered the overall humidity

Nice work I'd better add a bit more info We have a PIV unit installed - takes air from the loft and pushes it into the house - it's not MVHR but it solved the issue when I insulated under the ground floor and humidity levels spiked due to the reduction in drafts. It cuts off at anything above 25 deg in the loft (so summer during the daytime it's mostly off) It does a fairly good job run (08:30 to 15:00 provided the loft temps don't turn it off early) and 00:00 to 06:00 overnight when we are the main drivers for humidity (Sleeping) I've never calibrated the Humidity and Temp Sensors but from a temp perspective they are pretty damn close to other devices reporting temps so I'm comfortable with trusting the info What I would say is that all my humidity readings I feel are on the high side and I'd like them to be lower but when we ventilate the house on good dry and sunny days the readings go a lot lower into the low 40's (much lower than the loft!!!) Last thing the room with the sensor is heated in winter but on a set back temp to the rest of the house as it's north facing - has three external walls and loses a shit load of temp very easily (last winter it also had a large area off loft insulation missing) - If I'm in that room working on my PC it heats up quite quickly

As I said earlier I've been logging for a while My External Sensor (Tempo and Humidity) is actually in a well ventilated loft My Internal Sensor (Temp and Humidity is in one of the bedroom) Hopefully this table will work OK Month Avg External Temp Avg External Humidity Avg Internal Temp Avg Internal Humidity Aug-23 20 62% 23 60% Sep-23 20 68% 22 64% Oct-23 15 80% 19 67% Nov-23 9 89% 13 73% Dec-23 10 91% 15 69% Jan-24 8 86% 14 64% Feb-24 11 86% 15 67% Mar-24 12 79% 16 66% Apr-24 13 70% 17 63% May-24 18 66% 20 65% Jun-24 19 58% 21 59% Jul-24 20 61% 23 59% Aug-24 21 57% 24 56% Sep-24 18 70% 21 64% Interested in Mike's xls sheet I plugged this years data into it

I know it's an old thread - but I got a very good measurement of my heating circuit by reading the water meter before a refill after a drain down (I subtracted the volume of the header tank

Not wanting to take this thread off topic perhaps I should start new thread 😉 It's 5.4 Litres of hand built V8 - made a bit nuttier by AMG - then thrown in a car with a short wheelbase and not enough room in the arches for a more suitable width rubber so anything more than a moderate throttle lights the tyres up. 🤣

Luckily we have a fairly good one at my workplace and I've got permission to borrow it this winter - seems a bit pointless to look at much at this time of year - you really want to use one when the house is up to temp and it's cold outside to show the biggest leakages (IMO - happy to be shown to be wrong)

Amen Brother Stupid V8 in a silly car = Lots of fun

Pleasantly surprised lots of normal GD "stuff" was missing Zara didn't get pregnant You didn't got over budget but came under (OK not quite finished but close enough) The house was "finished" before target time The garden wasn't finished but the bones are there. I amazed GD didn't can the programme due to not enough drama 😉 I guess the look of the house and the corten provided that...... Well done

You are taking what I said out of context - yesterday "specifically" the boiler wouldn't work (so WC wouldn't work too) with all the TRV heads removed (I tried that in case it was a flow issue)

I was intending if it all works as it should to just use the decorators caps - she turns those it turns the rad off