richi

Oh, wait, I think you're right, sorry. My memory of the gas price is bogus. A good price for bog standard 28s kerosene delivered is 55p per litre. A litre has a touch more than 10 kWh of energy. however, the best oil boilers are less efficient than the best gas boilers, because they don't modulate.

Dated yesterday: Energy company faces losing licence over £3m debt Ofgem has given the company three months to comply and revealed an additional report also highlighted serious customer service failings. https://www.bbc.co.uk/news/articles/cr5q19geggno

I second @JohnMo’s suggestion: Consider air-to-air. I’ve recently installed a pair of 5kW Toshiba Haori splits—one at each end of the house. So far so good and my modeling suggests it'll cope with the coldest winters we've seen in this old house since we moved in 10+ years ago (and summer cooling without having to worry about condensation problems with fan coils). I expect to be a bit better than cost neutral, but even if I don't save money, I still needed to replace the 50-year-old boiler, the oil tank and a couple of manky rads. Caveat: I’m replacing an oil fired system, which is roughly 150% of the running cost of gas.

I've been very happy with this Computherm wireless stat/controller, originally recommended by the immortal Jeremy. Range seems decent; when last I checked there are repeaters available. [Amazon Associates sends a small kickback from qualifying purchases—at no cost to you—which are put to good use in SWMBO's dog-rescue charity]

I'll leave it to someone more knowledgeable to advise, but isn't 75 flow rather hot for a condensing gas boiler? Are you keeping an eye on the return temperature? But then if your rads seem to be hot all the time, one has to wonder where all that heat is going. Time to walk around outside with a thermal camera? Shame it's not cold now.

Are you timing the heating traditionally (i.e., off overnight and perhaps during the day)? Or are you keeping it on 24 hours "low and slow" (perhaps with a nighttime temperature setback)?

No, I haven't. You focused on one phrase in my reply, and your knee jerked.

That is exactly what he's saying.

It isn't. And I can't see how you could possibly draw that conclusion—unless you didn't read my original post.

Okay boomer. If you believe he's lying, that's another thing indeed, but you should probably present some evidence. The data he gives is a constant daytime room temp of 21, set back overnight to 18 (by reducing the flow temp).

Don't. The media scare a few decades ago was down to the inability to separate correlation from causation. Diseases of deprivation were found to be more prevalent in areas near pylons, but that's due to the fact that areas near pylons are more likely to be deprived—not that the pylons or EMF were causing the diseases. Occam's Razor, and all that.

I've bought several from the iBath range and couldn't be happier with the value and the way they seem to throw out the heat: https://amzn.to/3slvNQu [Amazon Associates sends a small kickback from qualifying purchases, which SWMBO puts to good use—at no cost to you] Not my picture:

I don't understand your visceral reaction. This isn't a grant job—it's an experiment to demonstrate how far modern ASHPs have come, and what's possible in "challenging" circumstances. Nobody's suggesting home owners shouldn't bother with insulation—but the data are remarkable despite the lack of insulation.

Yes but a rule of thumb that makes it "seem" flawed might not reflect reality. I gather that they were of the opinion that those rules of thumb weren't helping the industry, in the light of newer, more efficient HPs and better weather comp. So they did some calculations and used their office as a test to verify. And it's pretty encouraging, right? With some cavity fill and better loft insulation, they'd reduce the energy needed and nudge the SCOP perhaps into the mid-3s. All with no new pipework nor rads.

I'm guessing not, it being an office rather than a home.