MJNewton

Yeah keep going - you never know how useful this sort of exploration might be to someone else coming up the path behind you.

Might the details (or clues at least) be printed on the inside of the spacer bars?

What’s the temperature of the water reaching the radiators? Edit: Sorry - just seen you said 67-70c!

A common mistake!

Did you set the pre-charge pressure whilst the system was closed off?

Good grief - what a situation! Reading the post I was assuming it was going to be a repeat of what we often see - slow progress, not meeting expectations, differences of opinion etc - and then a discussion about how to break free without causing offence etc... BUT this one is very different! I am not a lawyer but personally I'd just run away as fast as possible without looking back. At best he sounds thoroughly incompetent and so I wouldn't have any fears about him chasing you for anything. Just in case, write everything down now about the sequence of events etc whilst it is fresh in your mind and file it away just in case it needs to be referred to again. I'd say the question really is how can you recover money already paid (or some of) but if you're willing/able to let that go to end the sorry saga then perhaps do so.

They do, but your house already has its own heating system which is likely to be more efficient (or certainly no less) than that provided by one in/around an MVHR. Even at relatively low supply temperatures (eg 16C like you say) I've never noticed a cooling effect from the system. It must of course being doing so, but it's not noticeable in terms of cold draughts etc.

😁

No, you're in good company! I retrofitted MVHR to a 'reasonably leaky' (never measured but it's a 2007 Persimmon with dot-and-dab plasterboard etc etc so can't be great) and it is superb. Were it not for the difficulties with such a retrofit I would unreservedly recommend it to anyone. Passivhaus published a research paper in 2020, whose summary conclusion was: If retrofit is a barrier then certainly worth exploring PIV too. This thread on the Pistonheads forum is worth a read - full of loads of people who have had great success with it.

I bought mine but got the supplier (Marks Electrical) to delay delivery and just store them in their warehouse. Think they had them almost a year, and whilst part of that was during the pandemic and so likely led to greater pragmatism, I never got the feeling they were in a rush for me to take them. I suppose they had my money, and of course an enormous warehouse. The approach was driven by my desire to buy at the lowest price and secure what can be hard to find items, but also not wanting the warranty clock to start ticking (Marks Electrical reissue re-dated invoices the day after delivery so no issue with registering the appliances for their warranties but the supporting receipt dates being way out).

Regarding the variable emissivity of the different surfaces, just put a small piece of black insulation tape on the surfaces to be measured and that’ll correspond well to the default calibration of the IR thermometer.

There have been quite a few variations of the 100-W over the years so probably worth being more specific when discussing them and referencing their model code (e.g. BK1F).

I’m signed in to Google but can’t see them. Could when they first went up though. Now that the edit window has closed just post them up again then we can move the discussion back on topic!

The measurement isn’t taken from the ridge, it’s the point at which a horizontal line from the flue outlet (centre of) hits the roof surface. It’s a bit late for me to do some mental trigonometry but I guess if the ridge is 7m away then the point of interest on the slope is likely beyond the minimum required.

It does look a little on the low side, compared to the roof slope. Optical illusion perhaps given the camera angle? The flue vent should be at least 1m above the roof surface and 2.3m measured horizontally.

They *were* working for me when first posted, but have now gone.

So nice to hear the expression 'like Blackpool lights/illuminations' again... Growing up in the North I think I might well have heard it almost daily in reference to lights being left on, control panels gone wrong, car dashboards etc (funnily enough, rarely if ever to describe street lighting!) and whilst I use the expression down South it doesn't have the same effect and inevitably results in quizickle looks/responses. Sorry I can't help, but I did want to thank you for the nostalgia!

I think their email has made it quite clear how long they intend/expect their product to last - and their willingness for discretion - so I can't imagine you being able to get anything further from them. The statute of limitations has expired too (6 years) so even if they were the supplier (and not just the manufacturer) a legal avenue of seeking recourse is no longer available. Personally I'd be looking at other products, not least given this whole thread is centred around what a poor design this particular stat is (self-heating, poor ventilation to deal with this issue, limited longevity (for reasons as yet unknown) so I wouldn't throw good money after bad and would instead use the failures as the motivation to jump.

Here's the installation manual, albeit not in English so you'll have to run the text through Google translate or similar! Edit: There are a couple of photos here too which may be of use, although it doesn't look all that difficult.

Not if you end up running the large machine at an output way below its sweet spot. Efficiency tends not to be constant across the range of operational output. Try doing the same journey in a 5L V8 - at the same (desired/required) speed - and the inefficiencies of using such an oversized beast for the task would become quite apparent.

(Tripped the file limit with the first pic so following on here) And then more towards the end once the distribution pipework had been put in (4 extract and 8 supply if memory serves) along with insulation around everything:

Sure! Anything in particular? As a starter for ten, here's the 'bare bones' unit mounted and with the primary connections made:

Mine's in a cold loft and performs perfectly fine, and consistently over 80-90% efficiency. It was a retrofit to so much harder than a new build, but I'd happily do it all again (well, okay, happily might not be the right word to apply throughout but most of not all of that is down to the extra challenges of retrofitting).

‘Analysis paralysis’? If so, yes, I’m a regular at that!!

Can you elaborate on that? It's not something I've seen/heard before. My understanding is that the primary driver for the location of supply vents is such that maximum cross-flow/mixing of air is achieved through the room thus, usually, being as far from the door (through which the air is ultimately expelled) as possible. The exception to this is large mixed-purpose rooms (such as 'family' rooms that might combine lounge, kitchen and dining areas) which contain both supply and extract vents, but again the same principle of maximising distance between supply and extract holds true.