marshian

I would not be happy with that if I'd done it myself!!! I'd be really Expletive unhappy if I'd paid for it to be done like that!!!

Can I have a bit more detail on this end of the graph please??

Yeah 13 TRV's managed by the hub and when a number of them get close to target the system goes into save energy mode and actually uses more For me on the old boiler (Glow worm) I'd dialed in 10 mins of pump over-run and in the shoulder seasons nearly 30 mins of anticycle time at the lowest flow temps I could realistically run (So as the POR runs concurrently with ACT a max of 30 mins between burns) This was down to 10 kW min of the boiler and a heat loss requirement of max 1.5kWh - I wanted to do everything I could to maximise the burn time and allow the system to coast for as long as possible And then when the boiler finally fires up Wiser says "oh no you don't" It nearly went in the bloody sea!!!

Whoa!!! You witnessed it doing that?? That's bloody nuts!!! I never got those symptoms - it would always switch off the call for heat (like a single house room thermostat reaching temp) - you would see the CH light go out on the hub - the pump over run would kick in and then 2 mins later the CH light on the hub would come on again and it would re-fire if the return/flow temps had dropped enough to call for heat.

So in a nutshell "smart" can be "really bloody dumb" - Anyway this is OT for the original post and I'm damn sure it's been discussed elsewhere

OK let me help @Nickfromwales The Wiser Hub has some "smart" functionality inbuilt into the software where it tries to save energy It's looking at the delta between "actual room temp" the TRV is feeding back to the hub and the individual target temp set point if the delta between them both is a very small the Wiser hub can turn off the call for CH. The boiler as a result shuts down and waits for the return temp to reach a point where it can fire again Trouble is this "smart" approach can result in additional cycling where none would actually be required so maybe "not so smart" It's bloody annoying to have a few rooms not yet up to temp and the boiler switching off as soon as it's just fired just because one or two rads as saying they are close to target. If it's installed in a house with a traditional higher flow temp (60/70/80) this sort of intervention will actually work quite well - it did when I was using higher flow temps and scheduled heating However in a lower flow temp system 30/40/50 it's very much an unwanted interruption to the boilers normal cycles There are a number of ways you can limit the impact 1. You can tell the Hub it's managing an oil boiler - that should drop the hourly cycle limit from a gas boilers 6 to an oil boilers 3 per hour (other options include telling wiser it's connected to an "Opentherm" managed boiler - it really cops the hump with that one and gives you a warning triangle on the app but it worked for me 2. You can restrict a couple of rads in areas not used all the time to never achieve the target room temp (thereby ensuring that there are always a number of rooms where the set point hasn't been achieved and this minimises interventions for the hub 3. You can set some rooms to have a higher target temp than can be achieved - your room temps in the app will go bright red cos of "overheat potential" but this is the "(expletive deleted) you wiser" option but in reality has same impact as 2.

OK so how close are the rooms to target temp? Is it wiser trying to minimise overshoot in room temps?

Some progress - the barn that it was stored in burnt down around it - front end was so soft I had to cut it away Shell has been shot blasted and etch primered - gathered an awful lot of parts for it over the last few years but retirement is still a few years away and other cars* keep me busy Oh that will go well * Other cars.....

I can understand why that would keep you awake at night but as you say if the job is creative and rewarding I hope the number of sleepless nights are minimal I'm with you on the fun bit - I work in manufacturing in a slightly weird role (started in manufacturing management - moved sideways into logistics and then sideways again into finance before my most recent role as a the sole business analyst but linked closely to operations As a result I deal with everything from automation optimisation, scheduling, costing (lab, RM and OH recovery) as well as capital projects - That might get me a a label of "A jack of all trades" and probably the back ground I have mean the std "master of none" doesn't actually apply 😉 For me it's a consequence of text or rather the English language being easily miss interpreted - emails can be even worse!!! I do try to see any comment as "meant in a good and constructive way" I find that helps avoid issues or poorly worded responses that result in tensions The Design guide was very useful and yes gave me food for thought The roof bracing is exactly as it was built - where boards intersect with the bracing - the boards get cut to suit 🙂 Anyway - I'm pleased to say last night I completed phase one - 1/3 of the accessible area is fully insulated and boarded - I can already see the difference in the ceiling temps of the rooms below (with an IR thermometer - only 2/3rds of the rooms below are covered by the improved insulation right now)

Well that was sub optimal!!!

Then it must be because that’s what your house needs to keep it warm 😉

Just to explain why you don’t see the same thing on initial heat up On initial heat up you have a cold circuit even if the flow is a little low (and I think it is) the water has a lot more capacity to take the heat from the boiler so it doesn’t overshoot in the same way - once the circuit has some temperature in it the capacity of the circuit and flow to take the initial purge and hi level burn before the boiler modulates down is much reduced

Nice - very nice indeed My retirement project is to restore this To as it was in the COI back in the late 80's But it has a bit of a troubled history

Regardless of the regs if there are any - both my ground floor flow and returns have drains out side if the house (actually under the decking in the rear garden) - conventional drain points - just foam lagged in case of freezing temps

Diagrams are handy - I'm pretty sure I have FInk style Trusses I took note - just had other things going on As far as drama and real life examples go - be careful using examples like cutting holes in aeroplane windows with a multitool - you might think it's humor/fun but it may not be received in the same way - that's the problem with text on the internet - you don't get to see the facial expression as the humor/fun is delivered the storage up there is pretty minimal (xmas decorations, empty suitcases, my stock of foam pipe insulation and the odd tote bin of things I don't want to throw away) and items are well spread out I'm not using it as another room but I do want to be able to get access to all areas of the loft easily - I'm not happy with 400 mm of loft insulation over the top of trusses so I don't have a clue where I can stand safely without putting a foot thro the ceiling below (that's why it was boarded originally) You raise a valid point but 30 years my loft has been boarded out and I've seen no evidence that it was in any way excessive loading - no sags or cracks in the ceilings They (trusses) are actualy marked up with manufacturer (swedish I think) and a BS std - I think from memory BS 5268 because the cold water storage tank is in the loft framed off the trusses - I need to check and note down the details One thing I would say they aren't the spiders web of skinny timber I looked at in a friends new build house - they looked like match sticks holding the roof up!!! Appreciate that it's my neck on the line and I do have a habit of "over engineering" stuff so the advice is appreciated

so you need to increase the flow rate thro the boiler to stop this overshoot - open all the lockshields 1/2 a turn (except the towel rails) see if that stops it - if it does wind them back a 1/4 and see how it reacts - if it doesn’t add another 1/4 turn and see if that helps if you get to a point where the boiler isn’t overshooting then you can drop the flow temp and you’ll get longer burns at lower flow temps but you’ve got to get the boiler happy on initial purge and burn

Mine (wiser hub) doesn’t any more - I set it to oil boiler and that halved the number of cycles -then set it on open therm boiler settings (even though it’s not wired for open therm) - that fixed it when I was running scheduled heating slots. Noe it doesn’t do it at all but I’ve set the majority of TRV’s to 0.5 deg above actual room temps and that can’t be achieved with WC flow temps But that isn’t @seanblee‘s issue I’m sure of it and it’s a bit off topic

9 cycles an hour between 12 and 1? And in the afternoon way more - I’d not be happy with that at all

I’d be doing something very different - I’d be sizing my rads for the lowest flow temp my boiler can run at but I’d be looking to do that for the whole house in order to get the boiler efficiency to high 90 % efficiency (ie 97-98%) that would make me heat pump ready for when the boiler needs replacement with just the addition of a HW tank (cos you currently have a combi so no HW tank) However I appreciate that everyone has a budget and sizing for 60 deg might be what your budget accommodates. I wouldn’t mix and match and have part of the house with oversized rads and the rest of the house sized for 60 deg C flows.

It's a different approach if you are using online calculators based on room volume then please be aware they will probably oversize the requirement. As others have said you really need to do a whole house heat loss - but if you are already running 60 deg flow for the rest of the house then I guess you need to size the rads for the new area with the same temp regime and just do a heat loss of that area. With your current rad positions you should get a good even spread of heat and as you say you can turn the rads down if they are a little over size whereas if you undersize a rad you can't really turn it up (all you can do is up the flow temp) or replace it for a larger one

Sorry fat fingers - same questions still apply

Anyway back to topic - what's the reason for using T11's @tommyleestaples Space constraint? Already fitted? Asthetics?

Same age but I cross over between metric and imperial depending on factors Really small stuff - Thou (I have a automotive habit so spark plug gaps and tappet clearances) Small stuff - CM and MM and to a push M Bigger stuff - Inches and Feet (Boats are still x footers and I'm 5 foot 13 inches 😉 ) Really big stuff - Miles (although knots and fathoms if I am boating) I don't do lbs and ounces - I do Kgs but weight in stone is much easier for me to translate in my head Still work out miles per gallon (the proper sized one not the poxy little one the USA use) even thou I buy fuel in litres It's all a little weird really!!!

Funny that - customers* are strange!!! * it's why I don't have any I have every sympathy for those that do!!!

I was a bit surprised at what I saw - quality control clearly not the best Sounds like they are functioning relatively well - verticals really do seem to need a bit more flow and a slightly higher flow temp than an equivalent T11 or T22 to get the same heat output Worth a look - I have a very large vertical (Millano) with a built in diverter and after my experiences above I had a good look in that one and it's 100% diverted