marshian

One more thing - the parameters for anti cycle d.2 don't have much impact at higher boiler temps but the pump over run timer d.1 is set to 4 mins as std (mine was actually set to 2 mins for some reason and used to cycle a lot) - I've now increased d.2 to 8 mins and it gives much longer time for the HW tank to extract out all the heat (once the flow and return temps equalise the boiler with fire again if there is still a call for heat regardless of the pump over run setting) it's around 6 - 7 mins before it fires again

Hi been reading this thread and your "zombie boiler" thread and found them very interesting Trying to keep this post short so I don't ramble on too much but in a nutshell I also have Glow worm Flexicom 24HX and am in a similar boat so to speak When installed it was running for several years at 75 deg flow temps due to T11 rads (legacy from the original house build) and a gas engineer who left the boiler providing enough heat but not optimised (probably never running in condensing mode) the temp was fine for CH or HW Last winter 4 T11's got swapped out for T22's and I was able to reduce CH flow temps to around 64 deg c and returns of around 45 but I had to heat water separately from CH by manually increasing flow temps to 68 which is a bit of a pain to have to do twice daily (return temps don't exceed 54 deg C) tank temp gets to high 40's which is fine for us as we pretty much use all the HW daily and it minimises losses (Tank gets a Legionaires once a week where the flow temp is set to 82 and the tank gets to just over 60 deg C) This summer a bunch of the remaining rads got swapped out for T22's or larger vertical rads in rooms with space issues (bathrooms and Kitchen) Now in the early autumn when CH is starting to be needed I can heat the house with 45 deg flow temps and 30 deg return temps - it may need to rise to 55 deg in the colder months but the return temps will still be lower and keep the boiler in condensing mode all the time. Controls is WISER with Smart TRV's on all but one rad although it now has an automatic by pass in circuit However HW is going to require the same manual work around again this winter so been searching the web for a solution and although I can't find the post I found a thread where an external weather comp sensor was used and small program / switch ran to change the resistance of the outside temp sensor to fool the boiler into ramping up the flow temp when HW was being called for I've found the savings in gas consumption between flow temps at 68 and several cycles compared to a higher flow temp say 75 and one or two cycles to achieve the same temp is minimal especially when the boiler is range rated down Wondered what your thoughts on the Weather compensation hack would be??

Hi All Joined to comment on a thread I found whilst searching the interweb but seeing as an introduction is required thought I'd throw a bit of background down Current house owned 33 years but updated over the years 1980's built detached 4 bed so originally open cavity walls, 25mm of loose fill loft insulation, single glazed doors and windows, void floor downstairs over a 2 - 3 ft crawl space and back in 1991 an annual gas usage for CH and HW of 25,000 kWh two floors with a total of 113 m2 (Small extension done in 2006 to building regs at the time) have reduced over the years with Double Gazing, Cavity wall insulation, upgraded loft insulation (could still be better), new boiler and replacement rads and spent 3 months last year doing 56m2 of 75mm PIR between the joists under the ground floor - amazing reduction to heat loss considering heat is supposed to rise 😉 Currently 8500 kWh gas usage per year for CH and HW but looking to use it more effectively rather than reduce it further