Barney12

I bought a non-branded 5ah one a while back. This one: Amazon Linky Its been absolutely fine.

Yes, I get that too. But that wasn’t my question! “So how on earth do the electrically charged ones work. Surely if the inbuilt immersion’s are firing 2.8kw of heat into this ‘liquid’ it’s going to heat up? If it doesn’t where on earth does that generated heat go?“

So, my question remains unanswered. Jeremy said this “This means you can keep pumping heat into it at 58 deg C until all the PCM has melted, when it will stop absorbing any more heat without the temperature increasing.”

Yes, understood. But continue to heat said bucket of ice (which is now water) and it eventually boils!

Interesting. I’m being a bit slow to catch on with how the Sunamp actually work. So when they are ‘charged’ the material is in its liquid state? So how on earth do the electrically charged ones work. Surely if the inbuilt immersion’s are firing 2.8kw of heat into this ‘liquid’ it’s going to heat up? If it doesn’t where on earth does that generated heat go?

Crikey. I must have a load of X10 kit sitting somewhere in a box. Considering how old the tech is now it was surprisingly reliable.

............So in summary; Velvac design means incredibly careful detailing of openings. Those very openings can be influenced by a number of factors/contractors. No thanks, there's already enough to go wrong on a build

I actually dumped Velfac exactly for this reason. I could never get a straight answer out of their technical team as to why they require a render first approach and I asked more than once! I have a trail of emails on the subject. If it is as per @the_r_sole says then this seems a design element not required by any of the other manufacturers I came across. If you’ve got an MBC frame and you’re trying to minimise any potential thermal bridge then you want the windows set into (or partially into) the timber frame with a damn good air tight seal. Velfacs design just makes that a lot harder IMHO.

That would be my preferred choice as you've got a downpipe anyway. Just make sure is roddable (is that a word?).

I'm not so sure. If he's like the many I've met then he will genuinely have no comprehension that he is doing anything wrong.

I'd be tempted to put a roof drain of some sort in. If using fibreglass (which in my view is a very good option) then something like this: https://www.roofinglines.co.uk/product/grp-rainwater-outlet-50mm?gclid=EAIaIQobChMI6qj_ntrO3gIVh9OyCh003QOgEAQYBSABEgIoi_D_BwE You can get them with stainless grates or cowls. EDIT: You need to think carefully about the drain position and run off of the roof section. IMO putting it in that corner where your bin store is would be 'less good' as your fall is still going to be towards the stairs. Equally any fall towards the house (and doors) is going to be bad. I hate to say it but where your gully is currently sat is probably the optimal position. The wall around the stairs is also a real potential water trap even with the drain in its planned position.

Im not sur there is a natural exit looking st the drawing? The only exit point appears to be a set of steps and I wouldn’t want that as my exit point, well unless you’re trying to create a water feature!!

I’m in Devon and alas the county has a good few of these ‘local time served roofers’. As they say arround here “you caint lernit”. Unfortunately a lot of them are more used to roofing farm barns than houses.

No, the Sunamps were pretty well charged at the point of wiring up. I agree further testing is required and thats the reason for installing the meters as I've had a sense something doesn't stack up.

OK, so furthering my quest for understanding...... Is there a way to know what (say) an average shower should use in terms of consumption. I appreciate there's lots of variables (i.e. temperature of water). The reason I'm asking these questions is that my Sunamps appear to using huge amounts of electricity. To give that some perspective: Since completing the wiring of the new board my two 9kwh Sunamps have used 34kwh of electricity, thats in less than 24 hours. I've deliberately left both 16amps circuits live (and have removed the solar diverter from the mix for clarity). So whats the consumption been in that period? Well I've had one shower (this morning), perhaps 5-6 minutes in duration. I've run a hot tap for aprox 20 seconds in the kitchen. I switched the UFH on yesterday evening for exactly two hours. (To provide further detail; the UFH circuit is fed by a TMV which is at its lowest setting, aprox 40 degrees. The UFH thermostats on the actual manifolds are set at 30 degrees. The temp sensors on the manifold fairly quickly were up to 30 degrees and the return pipe was warm, this would suggest the slab wasn't pulling that much heat from the UFH pipes?) If what is written in this thread is right then I could conclude that both Sunamps were depleted twice! Yet, as I've been monitoring closely neither unit went in to its cold start phase and none of my pipework ran cold. (I've checked the electric meter and that tally's to the din rail meters I've installed, so all working OK there) Confused!

I have another question in relation to energy use and monitoring: Are immersion heater elements 100% efficient? I.e. to use the example of a Sunamp; I have a 9kwh unit which has (i believe) a 2.8kw immersion. Thus is it a reasonable assumption that to fully charge this unit from cold it would take 9kwh of electricity? I appreciate that it wouldn't be 100% efficient as there is an element of heat loss.

Job done as per the recommendations on this thread. There's a fair bit of thread cross over with the thread on energy monitors (here) I'm not so happy that the 4mm cable seems to run "warm" when pulling for both immersions. Is that normal?

OK, so today I've upgraded my electrics to cope with two 16amp immersions and also added the electric monitors I wanted for each of the Sunamps. In the end I went with these (Amazon Prime eligible so easy to return if crap!): https://www.amazon.co.uk/gp/product/B013E007VO/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 They seem to be doing an admirable job. Oh and of course the requisite picture...... (Note: I really didn't need RCD protection but it was the only CU that they had in stokc which would fit in the space :))

I wouldnt, that looks like a 10mm packer?!

Yes, I have heard the same but been told there is no release date as yet.

Yes, you should have a primer under your tanking “goop”. It’s normally supplied in the kit. The tile adhesive goes straight onto the tanking goop. You need to stop the absorbency of the timber.

As long as the ply doesn’t move/flex (and knowing you I bet t doesn’t !) and the tanking is well adhered (ply really well primed) what you’ve suggested will be fine. I did exactly that on some ply bath panels in the barn some 15 years ago and they’re still there!

Pretty much the approach I had to take with my windows. A long hosepipe and blast them to simulate the wind and rain whilst the installers were locked inside the house to prove to them they leaked!

Hi All I want to be able to monitor exactly how much electricity my two eDual 9kw Sunamps are using. Ideally with the ability to log the data (but not essential). I'm not seeing this as a permanent requirement, just an initial testing/evaluation phase. So perhaps something with a CT clip that I could put round the live supply cable to each Sunamp (Would that work?)? Obviously one of the myriad of 13amp plug type units is going to be of no use. If you're interested in the reason why............. Well the Sunamps are just great in many ways but they have (in my view) a fundamental flaw. That being absolutely bugger all user feedback! Thanks to the (super simple) hack from @JSHarris I can now see if they are demanding power but thats pretty much your lot. How much power, how charged or discharged are they? Well you just don't know! In fact without Jeremy's hack they could be phoning home to ET and watching an episode of Friends on Netflix, you just wouldn't know, just a big dumb white box with its equally dumb little cream friend (the control box). I've gone down the "electric only" route. So my only source for DHW and UFH is the Sunamps. But what I need to do is work out the optimum use of solar and off peak electric. But, without getting a feel for how much demand (say) putting my UFH on for 2 hours is, that currently seems like an impossible task! If I heat my slab at night will I have hot water in the morning, if I'm relying only on solar charging alone? I'm not sure if I'm being overly clear but hopefully you get the drift!

Wagner designed and supplied all my kit for the solar arrays. I self fitted. Really good company to deal with.