DamonHD

About the same as an extra pane of glass. And if that window gets direct sun in summer, have reflective liners to minimise the risk of overheating then also. Rgds Damon

Indeed. Good to have what looks like a resolution LONG before we need space-heat! Rgds Damon

Thanks again for all the suggestions and discussion. C/o The Heating Hub today Tom Plumb London visited, and revived my existing expansion vessel at least temporarily. I've asked him (Tom) to come back in a couple of months and do a full service and replace the ev then if it looks like it's not holding up. But ... he's also a condensing combi and ASHP man, so we discussed those options if this Potterton packs in. He has seen the layout of the boiler area and house, and he's happy that something can be made to work. Rgds Damon

So harsh! I'll post any update here. Rgds Damon

Whatever is done will be by a grown-up eg GasSafe engineer. Rgds Damon

It's a Potterton Performa 24. Rgds Damon

For a while now the pressure reported by the combi has been swinging between 0 and 3 bar. When it gets low I gently top it up, but I suspect a failed expansion vessel. Rgds Damon

(We genuinely did have ice inside my bedroom windows until my dad did some DIY secondary glazing!)

I've tried telling them about ice on the inside of the windows when I were a lad in Yorkshire, and having to walk uphill both ways, but they don't believe me! Rgds Damon

Planning to add some USB heated insoles to my usual longjohns, double socks, fleece, etc. But the rest of the household may not be so keen on an Arctic re-enactment! Comments welcome! Rgds Damon

I disagree. It's a complex decision, and getting it wrong will cost lots more disruption and time and money and carbon than necessary. Having people list the alternatives and pros/cons has already been helpful. I *am* also talking to several possible installers in parallel. I don't want to wait to find myself with a broken system once it's cold and there's no available equipment or installers, and/or I need planning permission that takes months (and more money). Rgds Damon

Thank you so far. I've added another layer of sub-options / questions to my thinking! https://www.earth.org.uk/note-on-combi-replacement-dilemma.html#sub I can copy them in here if anyone thinks that that would be a good idea! Rgds Damon

Also a possibility, but that takes space that we don't have and/or will be ugly. But it may be the best worst option... Rgds Damon

That is what I would like to do. However the last gas engineer to replace the expansion vessel cursed about how the Potterton Performa 24 was laid out. It may not be possible to replace without removing the boiler from the wall, and thus disconnecting from the gas supply. At which point it may not be legal to reconnect it (non-condensing, non-boilerplus, etc) under new regs. (Also the old expansion vessel is a bit expensive and will take hours of expensive engineer time to swap out, likely.) Rgds Damon

Thanks all for thoughts and suggestions so far. I have started writing it up here... https://www.earth.org.uk/note-on-combi-replacement-dilemma.html Rgds Damon

That might be a good idea... Maybe you can infer what you're after from these: https://www.earth.org.uk/note-on-data.html#Unstructured

(Did I remember to say that our house is very small, including the kitchen where the current boiler lives!) Thanks for the comments above: I am thinking hard about them! Rgds Damon

Magic! Good heating controls, good IWI, always eg looking to buy the most efficient appliance when one needs replacing, some behaviour change, etc, etc. http://www.earth.org.uk/towards-a-LZC-home.html#todo Rgds Damon

(Thanks for comments so far!)

It has already had a number of repairs, and I will repair it if I reasonably can. Part of the problem is the way that this device is put together which makes the fix at the very least slow, but then also regs have changed since the last big repair was done... Rgds Damon

Hi, Our old gas combi may be on its way out. Our house is due to be bulldozed in 5Y, so ASHP upgrade extra punitive. We are already a low user (<3MWh DHW and space heat per year). Winter heat demand typically 3kW, peak ~6kW. Already have a heat battery installed (Thermino). Other gas appliances long since gone. Electricity is single-phase. What would the learned mob here advise: a condensing gas combi, an electric combi, something else? Obvs, I want to minimise carbon, including embedded/upfront carbon. I'm prepared to be a bit spendy to do that. Rgds Damon

PVGIS is your friend: https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#PVP Rgds Damon

An update: trying to pick the best fixed export (spill-to-grid) margin for my solar PV diversion to a heat battery: https://www.earth.org.uk/eddi-diverter-export-margin-analysis.html Rgds Damon

The way my system is now set up the heat store is a smalish Thermino (~2 day's DHW in a small unit under the combi) currently heated by PV diversion, but can be boosted from mains at appropriate times. The Intatec Intasol valve automatically draws water direct from the Thermino if hot enough, else via the combi (mixed down to 28C since my combi doesn't like hot input) as preheat. https://www.earth.org.uk/note-on-solar-DHW-for-16WW-UniQ-and-PV-diversion.html#2022-03-09 Gas demand has dropped from 4kWh/d to almost nothing (less than 0.5kWh/d). Rgds Damon

All storage (other than the Thermino heat battery) and inverters are outside the main living space, though the inverters are in the loft which might worry some as a hazard. (I asked the London Fire Brigade to check over the system as I had it at the time and they were content.) On the other hand, my insurers won't ensure anything outside even though I did point out that for (eg) Li batteries this is (a) common and (b) safest... I managed to negotate a compromise, but it's a bit silly... Rgds Damon