DamonHD

https://heatpumpmonitor.org/

Has the heater relay simply failed open/off? Rgds Damon

Here's a couple that I am using: https://www.earth.org.uk/MHRV-mechanical-heat-recovery-ventilation.html https://www.earth.org.uk/MHRV-Vent-Axia-Lo-Carbon-Tempra-P-REVIEW.html Yes, I think they do their job. Yes, I also see condensation dripping outside from the bathroom MHRV. Rgds Damon

FWIW, the boiler was fixed and then given a thorough service: https://www.earth.org.uk/note-on-combi-replacement-dilemma.html#2022-10-04 And should it actually pack in, sensible boiler man tells me that second-hand condensing boilers can be had for £200 or so. Rgds Damon

It should help. Rgds Damon

There's unlikely to be enough potential solar gain in winter to be significant: the insulation value of an extra layer of material probably outweighs it. Rgds Damon

I have used aerogel to good effect in my own home, in several varieties: https://www.earth.org.uk/note-on-Spacetherm-aerogel-thermal-insulation.html Blinds are unlikely IMHO to be air-tight enough to be much good to retain heat. To keep sun/heat out: https://www.earth.org.uk/towards-a-LZC-home.html#reflblinds Rgds Damon

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