marshian

Sounds to me like the boiler isn't seeing enough flow to keep it happy in the initial purge and high output phase unless the flow temp is set high enough that it doesn't overshoot (most boilers initial fire/purge is at 75% of max before they start modulating down) I had similar issues with a Glow Worm 24kW boiler which had a similar 10kW min - my resolution to run lower flow temps was to sacrifice the delta T at the rads - ie increase the pump speed and or and free off the rads will still maintaining the balance in the system. If you have an ABV in the circuit you could try increasing the flow thro it a little but ultimately returning flow back to the boiler via an ABV isn't great for efficiency Microbore to the rads isn't necessarily a problem (if it's just a short section from main flow and return that are 22mm) If your heat loss at around -2 is 6kW and the min modulation is 10kW it should be able to cope with that 10kWh with 6kWh requirement is going to run for ~30 mins in the hour with all rads in circuit provided you have the flow thro the boiler above the min which will be 10 lpm However once TRV's start to close the circuit size is going to shrink quite quickly Increasing rad sizes might make things worse - will result in rooms getting to temp faster if you can't get the flow temps down to work with the larger rads. A volumiser might help - it was in my plan to deal with the glow worm I had but as it was 14 years old I chose to replace it instead. I can understand you not wanting to replace a boiler that is only 6 years old I'd try increasing the flow rate thro the circuit first and see if you can get the boiler to cope with a lower flow temp and not overshoot on the initial fire/purge

Unfortunately many of them don't - they are "conditioned" to throw an oversize white box on the wall and set it up with S Plan No heat loss calcs to determine the optimum boiler size No weather compensation and HWP resulting in an elevated flow temp to cope with both HW and CH No optimisation of boiler settings to ensure the HW and CH requirements are matched to the boiler settings UK is miles behind Europe where this is concerned in so many aspects - even down to constant BBOE set up of Rads which loses 5% heat output. If you choose a Viessmann 100-W "Heat Only" my only recommendation would be not to spec/purchase a 11kW version (they can't be range rated like the 16kW or larger ones)

Sounds like the last AA meeting I went too

I'll be there around 7pm (depending on the work situation) If I leave work late I may chose the eat option - chicken curry looks like a good move (not a fan of Pizza)

Now that makes more sense turning them off and on again won’t be great for efficiency optimisation

When I worked for British Sugar we had boilers producing superheated steam to run a steam turbine to generate electricity - the “waste” steam was used to boil the sugar solution under vacuum until it crystalised and was spun off from the molasses It’s been a while since I was in that game but I guess the advantage was both the electric generated and the steam post turbine were fully used - even the condensate was recovered and put to use. Current work I was pretty sure our CHP unit (Combined Heat & Power) does better than that too (gas powered monster of an engine that runs a generator to produce electricity but again we use the engine exhaust heat to support our steam generators that also run on gas but have massive heat recovery systems on the flue gases. Still with a monthly gas bill the wrong side of £250,000 we need to minimise any waste in the system. When gas prices spiked as a result of the Ukraine situation our gas bill hit over half a million per month - that really screwed with our costs to manufacture products!!!!! I’m honestly surprised that a gas powered electricity generator that supplies the grid is as poor as 400g of CO2 per kWh generated - normally generation at scale is a lot more efficient

Either you have a unit of measure error or the gas power plant is bloody rubbish

last 3 years I’ve driven my gas usage down from 16,500 kWh a year mainly with insulation improvements and a bit of tech East Anglia is also quite mild compared to up north but not as mild as the pigs front legs so you definately have an advantage there. Increasing Loft insulation is my current project - can only do it in the winter as even in the shoulder months the loft temp with a large area of south facing roof space gets unbearable - going from a varable insulation level (patchy 70mm in 60% of the loft area and 200mm in the other 40%) to 320 mm everywhere but it’s slow going as I’m having to remove all the loft boarding Living alone is a huge advantage if your temp tolerance is quite high - mine is and I comfortable at 18 deg C unfortunately SWMBO isn’t and that means a compromise - I prefer a compromise that results in less noise 🙂

Good analysis - I’ve been doing the same….. last year (Act Nov 2023 to Nov 2024) I used a total of 8,250 kWh of gas for CH, HW and cooking heating to a tight schedule and putting up with a wide range of temps in different rooms - SWMBO did not like this heating regime at all and was rather vocal about it - she especially didn’t like going into rooms heated to a lower setback temp because used infrequently and as far as she was concerned the house was never warm enough - esp the living areas despite them being 21 to 22 deg C In Dec 2024 I went 24/7 heating with a much narrower difference between rooms (whole house roughly same temps - little lower in bedrooms and higher in bathrooms and living areas but interestingly at a lower set point 20.0 for living areas) Majority of Rads have TRV’s set to an elevated target (limiters) Boiler is running WC and room temps are managed by a constant flow rate thro the rads at a low flow temp rather than TRV influence at higher flow temps I’ve worked out based on 2 mths data that this change is going to cost me an additional £65 a year…… That I am very happy to pay it’s a cheap price to pay for improved comfort levels and a very very quiet wife 😉

Re-band would only be at the point you sell it normally?? Our house scraped into Band D - I did go thro the appeals process because it really should have been just inside C based on value at the time of banding however I lost the appeal (I didn’t do enough research and unfortunately during the review and appeal I’d already done some improvements which were included in error at review) It’s been extended now so sits firmly in band D so I’ve no worries about moving up a band if we ever sell it (been here 34 years now and no plans to move yet)

Excellent Thank you very much - I’ll send you a PM

Not watched it yet but heat geek talk about sunamps

on that basis I think I’ll treat your future blogg posts as thread resurrections in future

And once they do fail, as a customer of the failed company you get migrated to whatever company that is prepared to pick you up (or get told to accept you) and potentially that could be Scottish Power and I have no bloody wish to be back with them again so I'll stick with Octopuss

I know 3/10 poor rant - needed more variety in the expletives Sorry I'll try to do better next time!!

Ahh I was honestly wondering when I read the post what percentage of the population would still have concerns along the lines of your blog post - I could absolutely understand your concerns when Pandemic kicked off - fear is a massively powerful weapon and those in power in partnership with the majority of MSM and SM ramped it up to eleventy million percent with no real idea of the consequences of doing that. Lockdown should have never been the answer - we will be paying for it for decades in terms of health and wealth. If anyone is interested (and most probably aren't because they want to put the whole thing behind them) My first trigger point was the "daily death numbers" being announced on the News like it was a tsunami of epic proportions because there was no context - I new the context already 1600 people die per day in England and Wales of natural causes and the News was trumpeting anything from 1 to 100 deaths in a day as "end of the world" stuff - how the feck does the deaths of less than 5% of the normal deaths per day get to be headline news 24/7 A cruise Liner the Diamond Princess gave everyone a a perfect petri dish to illustrate who was at risk. - the results didn't fit with the narative that "those in power" wanted to "spin" so it was dismissed as too small a sample The original pandemic plan got ripped up and thrown in the bin in favour of "the science" which wasn't Science at all BTW Any challenge to the "new science" (like GBD) was labelled "crazy" and "internet was cleansed" to stop the spread, the authors labelled "fringe epidemiologists" Those in authority got "drunk" (in some cases literally) on the new power and did everything they could to keep it whilst themselves broke the "guidance" the set for others How often was a lockdown implemented after the infections had peaked? We were led by a government of muppets and the opposition party instead of doing what they should do which is "hold the muppets to account" and challenging the "rules" introduced instead cried "more more more" My second trigger point was when (having had Covid and recovered) a vaccination against Covid was required for my future well being............. Me "Sorry I need a "vaccine" to stimulate an immune response so I am protected from something I've already had and recovered from - surely that's what post infection immunity has always been about." (Ahh yes it was called "natural immunity" and we can't have that it indicates that people already have immunity and this is a new virus that has escaped from a lab doing US sponsored gain of function on coronavirus's research Sorry of course it was an unfortunate consequence of someone eating bat en croute or Pangolin lasagne Jedi Mind trick "this isn't the lab you are looking for" Third trigger point - The insistence on vaccinating every man, woman and child - Encourage by the Well if you won't volunteer for a vaccine "you really do need" we will restrict your access to travel and entertainment events in order to encourage you to have one The general public banged pans on doorsteps for the NHS who became the National Covid Service (concentrating solely on that and directly shortening the lives of anyone who had routine checks or any other screening process) I lost two friends - not to covid but to missed MRI's or other routine health checks that by the time they restarted the delayed findings were too damn late for them That's before I even think about the initial reaction of hospitals pushing elderly patients back into care homes - like that was a (expletive deleted)ing good idea!!! If you hadn't guessed all of the Covid "over reaction" really really really (expletive deleted)ing boils my piss!!!!!

Boiler is on a burn - pump is circulating - my question is where is the heat going if it's not going to the rads??

Those heat losses seem really high unless they are massive rooms I used the Heat engineer software (before I was aware of the spreadsheet on here) and it didn't seem like a steep learning curve to me I'm using flow temps of between 28 and 35 with T22 Rads and bedroom temps are set 2 deg higher than the std 18 for bedrooms I think I'd be trying to run the house with a single boiler temp for both UFH and Rads

it’s not hit and miss at all - 4 butts all fill to within 5mm of the lid before they just internally flow back to the soakaway, they normally come with pretty clear and easy to understand instructions Having said that I’ve mostly got flap diverters - so I can switch off the flow to the butts in winter

I think he was refering to the Smart Thermostats as Holy Grail - They aren't and it's very easy to over zone and screw the boiler efficiency Absolutely ^ this ^ - Running the lowest flow temp possible to maximise condensing efficiency improvements Do Baxi not have their own controls to enable PDHW because if they do I'd be using that - in fact I'd always favour manufacturers controls over 3rd party ones. The only reason I have a Wiser system is previous boiler manufacturers controls were archaic because the boiler design was 18 years old - when I change the boiler I stayed with the 3rd Party controls because I'd learnt a lot about what not to do!!!! "Experience is what you get when you don't want it"

Well I don't like having rooms unheated - it makes other adjacent rooms have to work harder but I think part of your house must have a one pipe circuit (maybe house extended or poorly executed circuit extension) but I was in this situation and I really wanted to do this I would do below Turn of the CH and Pump. Isolate both flow and return valves on the rads you want to stop having on - Drain down the rads and temporarily remove to make life easier. Make a simple link pipe up to fit between flow and return on those rads - Open up both ends fully All my rad tails come up from suspended wooden floors so I have enough room to push the pipes down and then hang the empty rad back on the wall It (the bypass) will provide a very small amount of heat input to those unused rooms but should stop the issues you have with turning them off impacting rads later in the circuit. (if you want to minimise that heating input then lag the pipework but I'd say a little heat wouldn't hurt)

I agree longest length of beading first then shortest - reverse for assembly but I’ve always put a wallpaper scrapper blade in the middle of the longest length - never tried one side as your picture shows??

no you need to replace the sealed unit - with same size and thickness sealed unit The frame is normally unchanged

I really regret not ducting my roof rainwater drains to a couple of IBC's under the patio - instead of filling the big hole up with brick rubble and old broken patio slabs (soakaway) I have 800 Litres of rainwater storage (mix of butts and tanks for spring summer autumn watering) and I always run out in the summer - mainly because I have to empty them all in the winter because of freezing issues and I'm reluctant to switch them to collection before April. They fill up real fast when it rains to a point that the excess often goes to the soakaway because they are full. The IBC's being underground would have been highly unlikely to reach freezing point and I could use them to top up any above ground storage in the summer. When we run out in summer I end up filling them with a hose from mains water. Should have done that IBC thing I really should!!!

I know this is probably a daft suggestion but I've always wondered in a house with UFH and Rads why you can't run the flow thro the rads first - then the return from the rads feeds the floor (with whatever flow it needs) the return from the floor combining with the return from the rads that didn't go thro the floor. So in my house (all rads) if my upstairs rads were the only rads and I had UFH downstairs the boiler flow would be between 30 and 35 dependent on OAT - the return would be 25 to 29 at same OAT The UFH could have as much flow as it could take - the return from UFH mixing with unused return from the rads? Like I said daft idea................