marshian

To use your own words you'll get over it

No - it was most excellent

My approach would be 1. lower pump speed (I hate system noise and if you are running 24/7 with setbacks it’s costing you money via higher wattage drawn by the pump) if boiler overshoots 2. open lockshields a bit more but with 9 or so rads in circuit you really shouldn’t need a high pump speed and the balancing should be fairly easy to achieve Then with a stable system circuit running quietly I’d start to back down the flow temp - as you do this your individual rad deltas between flow and return will drop anyway so don’t be tempted to tighten the circuit to keep the same 10 deg delta heat geek had a really good table of what to expect delta wise at the boiler at various flow temps - it’s a really useful table that stops you from fretting about low delta T at the boiler. As you drive the flow temp down you might need to adjust the boiler hysterisis but you are doing that to be inline (ish) with the circuit flow and return temps (to get to a point where the boiler doesn’t spend ages coasting while the circuit cools) all of the above with an eye on keeping the house comfortable temp without long recovery times after a setback at night

Little bit of info here - easier than explaining it https://www.pistonheads.com/gassing/topic.asp?h=0&f=47&t=1911876&i=0

Me too so you won't be dining alone 😉

The BBC covered the cost of a full set of tyres, a set of brake discs and a new clutch....... Just to clarrify - I purchased it direct from Lotus a year later (following a sealed bid auction process - which I didn't actually initially win) as part of a "fire sale" of all the Lotus "collection" Like I said the car has an interesting history - looked at from completely honest perspective you could probably say that technically it's not even a real one as it was not part of the original run of 950.

Name badge is at the ready - see you at 7 (ish)

That picture was at Shelsley Walsh Hill Climb It's mainly a road car but it gets used for sprints, hill climbs, track days, navigation rallies and of course European road trips - it however the tattiest LC in existence because of that - it's also the last one ever built by lotus but that's a story all on it's own......... The montage below was from a "year in the life of an LC" - I'm not precious about it - it's a car not a museum piece - I hate show and shine but it has done a few over the years - prefer to use it as intended - I've owned it for 24 years (bit of a love hate relationship and I'm never sure who is actually the abusive partner) Also might have been abused by someone else for a TV show

Important thing (stating the bloody obvious) is the boiler has to get the house warm - no point having a boiler thats tweaked to the max to give longest burns possible at lowest flow temps if the house is cold………. I reckon you’ll be able to reduce the flow temps along with a few more tweaks and maybe even drop the pump speed too last question are the lockshields reset to where they were or still a 1/2 turn open more?

That’s better - still probably things can be tweaked but I’ll take that as a win

We posted at the same (or similar times) thanks for the further explanation even before I'd asked the question

ahh OK so in doing that you "hopefully" minimise the distance to travel and with the pipe size minimise the volume of water that needs to be displaced before you get HW at the tap No pump?

OK and radials - a loop of pipework without a pump (so reliant on convection currents?)

Any chance of schooling me in what a TMV is? Long time bug bear of Mrs "Alien" is the amount of water she has to run off in the kitchen before she gets hot water - despite the VC being directly above the kitchen the Hot feed takes the long way round via bathroom first in 22 before reducing to 15mm going 2.4 m down a boxed section to feed first the downstairs toilet then utility room and down 1.0 m and then 6m across the house under the floor to get to back up to the kitchen sink All the pipework runs are insulated.......

Much better 11.2 kW - will it go down to the absolute min? Different ways of doing things - room struggling to reach target temp - my first reaction is to increase flow thro that rad ACT probably pays to be a bit mathmatical ACT of 5 mins means a max number of fires in 60 mins is 60 / 5 = 12 now of course the burn time is going to reduce the number of cycles but even if the burn time is only 1 min each time it'll drop the number of cycles to 10 per hour so idealy you want a burn time of 5 mins or more to get below 6 cycles per hour. If you aren't achieving that then consider increasing the ACT Hysterisis 15 deg might help - boilers only tend to get fussy when the delta between flow and return goes over 20 deg OK it's handy to have that understanding Normally I'd say do one thing at a time but in your case - throw everything at it to see what happens - it's an easy step to reset to factory settings Not a problem at all If I could comment some of this detail would have been good to have known in the first post of the thread - yes it would have made it a bit wordy but it might have saved a bit of time. What I really am interested in is if the purge and initial burn is still at an elevated boiler kW output...... My current boiler hits the circuit with 60% of the boiler max for 90 secs - it range rated to 5.86 kWh - so it's still smashing ~10kW at the circuit for the first 90 secs My old glow worm was 75% of max for 30 secs trouble is that was 18 kW - pretty damn hard for the circuit to deal with that if the overshoot is only 14 deg away

It's a 30kW boiler for CH so 40% of 30kW is 12 kW - do you really need 12kW to cover your heat loss and allow a little for a reasonable recovery time - Im surprised you can't range rate it down to minimum - the manual seems to indicate that you can range rate to the minimum?? Anti cycle time - decreasing it makes no sense - longer is what you want It's the time the boiler waits out before restarting On some boilers once the flow temp and return temp get down to 10 deg below set point they fire anyway I'd also look at the Anti-cycle flow temperature differential and consider increasing that to give a longer coast period via a lower restart temp. I don't know your boiler like I know Glow worm but GW/V pump over run gets first call followed by ACT so I'd start with adjusting PORT - it didn't have the Anti-cycle flow temperature differential adjustment so never got to try that OK I did wonder if it's always been like this or something new. It's only 4 allen bolts to take the pump assembly off the body (oh and an isolate and drain - you don't need to take the pump out of the boiler - just remove the motor and impellor from the pump body

Went googling - installation manual was rubbish, user manual equally so that you tube video gave me a big clue Turns out all the interesting set up stuff you can do with boiler parameters range rating Anti cycle Pump speeds and modes Pump over run time Greenstar_CDi_Classic_Engineer_Service_booklet.pdf

One more thing - has the boiler been range rated down for the CH side of the boiler?

Never have an issue with that - wind them in and if you feel the board lift - back em out and then bang them in again. I'm sure I will

I'm not concerned about rooms over shooting Evohome can do what it likes but if you still have a situation where the flow temp spikes when the boiler shortly restart overshoots and shuts down quicky then clearly the circuit still has a restriction to flow that the boiler is not happy with. You also say the system is noisy - now normally that would indicate a strong flow thro the circuit and I wouldn't be looking there but now I am. Let me show you my issue when for a reason I didn't understand I had to wind up the pump to speed 2 in order to stop the boiler short cycling due to temp overshoot. This massively increased system noise Now admittedly the pump had been in there 15 years and there was a magnaclean installed a couple of years before I found this but it was installed after the pump......... The system noise kept SWMBO awake which is sub optimal and also annoyed me as the system had always been whisper quiet on the lowest pump speed Cleaned out (and there was a lot of stuff in the vanes you can't see) I was able to drop back to speed 1 and the short cycling stopped Not say this is your problem but whilst Evohome is almost certainly cycling the boiler the over shoots aren't down to Evohome

They don't look sodden but then you've not got to the one near the drain? I was trying to work out if the floor is ply or OSB but either way I would not expect tile grout on wooden floor to be acceptable as a wet room...

looks at location - thinks "Blimey your are a quick driver.................."

Yes it’s still cycling but the important bit to consider is if the boiler still overshooting the set point with more open rads?

No shank for the boards to rub on - threaded from head to tip 😉

Interesting but my set up never did that - it would just intervene when rads were close to temp - knock the boiler off for anywhere between 2 and 8 mins and then call for heat again like nothing ever happened. That was enough to annoy the heck out of me hence the various approaches I took to limit it's influence over the heating circuit I'm almost 100% sure it hasn't intervened at all in the last 2 months since I've been heating 24/7 with TRV's set to elevated room temps (that the weather compensated flow temp from the boiler cannot hope to achieve) If it had intervened then I'm very sure I'd be removing it all and going back to a simple clock timer set to a heating schedule for the shoulder months and switched to constant "24/7 On" for the winter months