richi

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.

Sorry for the cross-post: That's the second time I've forgotten ASHPs are classified as "energy generation" on this forum. Weird.

Notes from video description and nuggets buried in comment replies: SCOP 2.99; "very small radiators, no cavity insulation" (but some attention to air tightness I suspect). "Vaillant Arotherm Plus. The load is about 6 kW … 22mm pipe." (He thinks the Vaillant HPs are much better than Mitsubishi, but more expensive.) "It was a pretty much consistent 21c internal temperature internally all week." "Weather compensated … curve selected is set for around 55c at -1." "I think once this has sensible radiators the SCOP will be more like 5." "Run 24/7 … set back overnight at 18c … does not turn off but lowers flow temp." "Electrical consumption in Dec … 580 kWh" Any TRVs left on max, ASHP modulates the flow temp down to what's required to maintain room temp. "I have not, nor will not state that insulation isn't the first most important step. By releasing this video I am not saying technology first. … We did not insulate first as this is not a house. This is a showroom. The heat pump will return before insulation and insulation does not fill the showroom." Sorry if you've seen this before. Sk8rboi has some other good content in the channel.

Cute unit, but how noisy are those all-in-one heat pumps in reality? The page suggests 58 dB(A), which might be irritating in a small space.

Three years ago, I put one of these in to cover a large open-plan conversion: https://www.vent-axia.com/range/hr200wk Works well, and reasonably quiet on low speed. Wire in a boost switch to make it spin up to max.

I used the Stiebel Eltron instant undersink unit:

As a rather confused friend of mine once said, "It generates up to 4 kWh per hour." ?

Oh yes, good point, @Temp. Don't pay full price for the Combimate unit, nor the refills! FleaBay and Amazin' are your friends.

A couple of years on, and we're still happy with the Combimate. As @Jeremy Harris rightly says, it doesn't soften the water, but it does seem to stop scale sticking to taps, etc.

Rules of thumb and arm-waving begin: Oil costs about 7p/kWh after allowing for boiler efficiency ASHP costs about 4p/kWh assuming electricity at 12p/kWh and COP=3 But ASHP runs at lower flow temps, or COP decreases, making cost about the same as oil. So a retrofit is tricky, unless you already have oversized rads. That's my oversimplified way of looking at it, anyway. Happy to be told otherwise.

I'm now two years into my whole-house Combimate installation (which reminds me: It's time to buy new phosphate balls). I'd call it a qualified success. In a hard water area like this (north Hampshire), it makes it easier to clean the taps and things. The calcium doesn't stick, nor make crusty deposits. It's not magic, but it's a lot less bulky and expensive than a softener. Running costs: The phosphate-ball refill costs £25/year. Perhaps £50 if you used enough water to justify replacing them twice a year. £0 in waste water for regeneration, of course.

https://blog.planningportal.co.uk/2019/05/16/time-limited-pd-rights-for-rear-extensions-made-permanent/

He's here all week. Try the veal.

About emptying septic tanks: I was always told that, so long as you don't poison it or flush things that don't biodegrade, a septic system shouldn't ever need pumping out or desludging. Discuss.