marshian

Are all your rads on pipework above the skirting? Only thinking back to your balancing issues it should be relatively easy to draw up a flow and return schematic?

Oh I'd have laughed about that one too (in sympathy * rather than at you) * Note - I left a valve on a "magnaclean assembly" not fully open once - Boiler didn't like that at all - luckily it was the previous boiler cos it didn't half kettle when it tried to run!!!

From a post from @EinTopaz above

https://www.youtube.com/watch?v=eqf7A00XXTU

Lot to go at there............. For a boiler to get to 70 deg flow really quickly yet the rads don't get there as fast is a bit odd - have you got an ABV in circuit that is allowing too much flow back to the boiler?? Why are you running the CH circuit at 70 deg C - that's way too high to get condensing benefit Whats the return temp coming back to the boiler? Could you list out Room / Rad Type / Size / Comment By comment I mean if it's a rad affected or one that seems to be fine all the time Vertical Rads are a whole different ball game if they don't have diverters in them If you can borrow a thermal camera it might give you some good clues on the flow internally thro the rad Below is one of my K22 or K33 rads running on a flow temp of ~30 Deg C And here is one of my vertical rads (with the modification internally) Below is a link to the issues I had with 2 vertical rads that were fitted with a diverter

Whole load of pain in that picture - my sympathies. You haven't fitted a water softener in the last 12 mths have you? I had a similar experience with my cold water store tank when I fitted one - the softened water removed some limescale that had clearly built up over a while sealing up a leak

Which specific model? Max Heat Output? Do you still have the installation manual for it? (because if you do that will tell you exactly what min modulation is) If I look on line for installation manuals - the range of min modulation across different version is pretty damn large - Some have min modulation of 3.7 kW on CH others are as high as 11kW depending on the Version (Peak Output) IMO you will struggle if your actual boiler doesn't modulate down to a min of around 5kW - you'll almost certainly need a volumiser to keep cycling to a minimum. Many Combi boilers have massive heat outputs to meet the needs of HW but this compromises the space heating side (CH) of the boiler.

Jesus - that's shocking - surely the set up can be easily changed to a lower flow temp is it a combi, system or heat only?

I have plume management kit on my viessmann boiler 1m height because I wanted to fit a car port on the side of the house - old boiler I couldn't get a plume management kit so boiler replacement was the only option It's 90 deg to the house wall - It also has a cctv camera looking down that wall to see the garage cctv camera is just below the 5.2 on the image above looking back at the attached garage You can clearly see the plume management pipe in white Only when I'm doing the HW cycle does the camera pick up the plume (DHWP so it does it at 80 deg flow and max kW) Rest of the time there is no plume at all because the flue temp is 24-26 deg C (Flow temp max 32 deg C return temp ~26 Deg C) I think if you have issues with excessive plumes from the flue then you might be running the boiler a bit hotter than you need to

On PP3 (out of 6) I've been checking pump parameters and I'm seeing variation from 0.3 m3/hr to 0.6 m3/hr on the same setting (ie unchanged) I maybe expect a smidge more flow when all rads are in circuit and maybe a smidge less flow when it's just the 24/7 rads in circuit but not that level of change....... I need to get my head round the PP element of pump control

Wrote a long reply and for some reason the forum or I had a blip and it never posted.......... Rooms/areas highlighted in are the hallway, stairwell and upstairs landings - they are all supplied by one ground floor rad I've amended the file to clarify which rads are 24/7 and which rads are scheduled (so only heated when needed) Rooms & Rads.xlsx Well I'm not following that and I need to get my head round it One thing I have noticed is on PP3/6 the m3/hr number varies a lot - can be as low as 0.3 m3/hr to as much as 0.6 m3/hr which is also confusing me!!

This thread is going off on a bit of a tangent PS I really don't see the issue - good use of an otherwise underutilised space

Looks to me like it could go higher (anticlockwise)

Adjusting the flush volume for short flush and long flush get them in the right orientation and the flushes are both the same volume (expletive deleted)ing hate modern toilet flushes that are supposed to save water with a 3 L short flush and a 6 L full flush - no-one ever uses the short flush and it won’t clear a good piss from the pan and don’t get me started on a number 2 that needs 2 full flushes to clear the pan give me an old ceiling level thunderflush any day

Which is exactly why the internet is bloody wonderful 😉

I assumed Glock or some other sidearm

Yeah years ago I’d pay to search companies house for home addresses of directors and send them a letter to arrive with their cornflakes - life is different now

Adam runs Heat Geek - you can contact him via the heat geek web page - he's pretty passionate about installs if any "heat Geek" accredited installer is over sizing a unit I reckon he'd be wanting to understand why

looks like they are trying to comply with MCS grant rules with what they are suggesting ping an email to Adam he’d probably respond with some advice

It was really a rhetorical question rather than an actual question - but thanks to those who responded

Yes I do - actually every damn rad dimensions and T50 output is in a spreadsheet I used it when I was working with the heat loss v rad output at various flow temps to work out where I needed to target the flow temp for the weather compensation at -2.4 Deg OAT Some of the individual rads I've tweaked the flow rates from where it was but overall system balance has remained the same. Front Hall, Toilet, Utility and Study remain on scheduled heating (heat loos of those rooms is a lot more because 3 external walls all on north facing side of the house All other rooms 24/7 Heat loss is overstated due to the software wanting higher ACH than I was comfortable with..... I also utterly badgered the dining room calc gave it a vaulted ceiling with no heated room above - Ooops True heat loss is absolute max 4.0kWh at -2.4 Deg C OAT (probably 3.6 kWh based on actual energy used if my monitoring is more accurate) Rooms & Rads.xlsx

Former yes - Latter no TRV don’t intervene on majority of rooms - WC flow temp and elevated room targets that cannot be hit with WC flow temp and heat loss of the rooms. So cycling was down to the house/rads not getting rid of the energy in the circuit. was first warm night 8.5 deg C so boiler flow temp would have been 26-27 deg C max and heat loss of the house maybe around 1.6 kWh (so on that basis I’d expect the boiler to fire for 15mins in the hour minus temps over night and it’s firing 45 mins in the hour the 9 cycles might be a one off or I may need to tweak the curve a bit more to align (lower) the flow temps at higher OAT

Typically my delta at the boiler is 5.5 to 7.0 max Start of burn it's wider, just before the boiler shuts down it's narrower - I tend to quote only the narrow end or give an average Last night it had a much cooler circuit to start from I might have to up the pump speed by one as between midnight and 8am the boiler fired 9 times compared to it's normal 7 or 8 max

I really like this idea - however when I was fine tuning my radiator flow rates I stuck matt black insulation tape on them so I could get a more accurate reading from the IR thermometer - Mrs Alien was not happy with "the look" so they didn't stay on there long - apparently they lost adhesion and she picked them off the floor and put them in the bin and I wasn't to do it again The description "Who is this for? These instructions are for ONLY if you: ● Have a gas condensing combi boiler. ● Do NOT have a hot water tank. ● Have no one ill or very young or very old in your home. ● Are willing to help us with an experiment to help save gas." Needs a bit of an update - they would also be suitable for any boiler set up with DHWP (with a HW Tank) and Weather compensated CH flow temps

Actually before that - the data doesn't show a two storey extension we threw up on the back of the house increasing the footprint and increasing the number of external walls on two large rooms It was built to building regs at the time so I expect a small increase in energy usage but I got a surprise it went up a lot That set me on the path of improvements to fabric and optimisation of boiler (eventually replacing a boiler which was no longer well matched to the house heat loss and cycled like crazy) I'm pretty sure it's 80/20 (fabric/boiler) - energy usage has actually gone up for 2025 (prob 10%) I'm heating 24/7 with WC for CH and DHWP (previous to this I was heating to a schedule) Room temps are higher than when I was heating to a schedule - comfort factor is much better I'm now in the final stages of increasing loft insulation from 70mm to 370 mm (long story not for this thread) so I hope that next winter the benefits will show up in a reduction of energy usage