Sunamp catastrophic failure . . .

[Onoff]

4 hours ago, Jeremy Harris said:

It's almost certainly just sodium acetate trihydrate, as everything about is is a perfect match for that compound.  Same melting point (58°C), same safety assurance, the stuff even tastes the same (don't ask me how I now know that!).  They originally gave it some daft name to try and make it it was some sort of magic compound and it seems they've now taken to calling it "Plentigrade", almost certainly just for marketing reasons.

 

Salt 'n vinegar crisps? 

 

Found this that suggests SAT in it's raw state can suffer issues. I don't for a minute pretend to understand most of it but it seems to suggest SAT needs certain additives to be used successfully as a PCM.

 

https://pmc.ncbi.nlm.nih.gov/articles/PMC7040703/

[Declan52]

Welcome back Jeremy. I'm glad you got your issue sorted. If I remember was one of sunamp main guys not a member here for a while. 

[Onoff]

5 minutes ago, Declan52 said:

Welcome back Jeremy. I'm glad you got your issue sorted. If I remember was one of sunamp main guys not a member here for a while. 

 

If was @Andy T iirc. He retired from Sunamp circa 2018.

[Jeremy Harris]

54 minutes ago, Onoff said:

 

Salt 'n vinegar crisps? 

 

Found this that suggests SAT in it's raw state can suffer issues. I don't for a minute pretend to understand most of it but it seems to suggest SAT needs certain additives to be used successfully as a PCM.

 

https://pmc.ncbi.nlm.nih.gov/articles/PMC7040703/

 

 

Interesting stuff, and does tally with comments that the secret to making a practical PCM thermal store was the additives used.  AFAIK, Sunamp have never openly published what those additives are, presumably this is a part of whatever deal they did with the university.

[Jeremy Harris]

6 minutes ago, Onoff said:

 

If was @Andy T iirc. He retired from Sunamp circa 2018.

 

Wasn't it @Andy T who had the same problem with his Sunamp?  IIRC it leaked all over the floor of his conservatory.  His will have been an earlier model of mine, as I think he had it as some sort of trial, much as I did originally.  I think it may have been some sort of special, too, perhaps one of the PCM34 models that got dropped eventually.  I remember seeing a photo of the goop all over his floor, if it is the same person.  I met him face to face at the Swindon self build centre, some time after I'd installed the Sunamp, as I remember having problems with the charge points there, which will have been when I had the little BMW i3.

[Declan52]

53 minutes ago, Onoff said:

 

If was @Andy T iirc. He retired from Sunamp circa 2018.

You have a better memory than me!!

[ToughButterCup]

Welcome back @Jeremy Harris .

 

Not to worry about the back-story : we'll kill the fatted calf anyway.

 

 

image stolen fair and square from Wikipedia

[Jeremy Harris]

I've been trying to see if my theory about these issues being related to pressure might be born out, by comparing the specifications for the UniQ that we have and the newer Thermino (which seems to use essentially the same, or an extremely similar, core design).  It's interesting that the pressure specs have changed.  The UniQ has a minimum pressure of 1.5 bar and a max pressure of 10 bar, according to the last set of MIs I received, version 2.0, dated 17/06/2018:

 

 

For the Thermino though these pressure specs have been very significantly reduced, to a minimum pressure of 1.5 bar but a maximum pressure of 5 bar, half that of the UniQ:

 

 

Moot point for us, perhaps, as our well pump can only deliver 3.5 bar maximum and the pressure regulating valve has always been set to 3 bar, same as the pressure recommended for the Thermino, but it does suggest to me that there is a known pressure sensitivity issue.  When combined with the emphasis in the new MIs that mandate the fitting of a pressure relief valve, set to 6 bar, together with the 0.5 litre pressure vessel I'm now more than ever convinced that the most likely cause of this failure is pressure, most probably some sort of repeated pressure shock from something like the shower turning off.  Although we have a 100 litre pressure vessel only a metre or so away from the Sunamp, it seems possible, perhaps even probable, that this is too far away to mitigate some sort of fast pressure shock wave.

 

This is all really just theory, but it does pretty closely fit with the known facts and details from Sunamp, and the experience of Jonathan Porterfield up in Orkney.  Why else would Sunamp have reduced the maximum pressure permitted, and added these over-pressure mitigation devices, if it wasn't because over-pressure can cause issues like this?

[Nick Laslett]

20 minutes ago, Jeremy Harris said:

For the Thermino though these pressure specs have been very significantly reduced, to a minimum pressure of 1.5 bar but a maximum pressure of 5 bar, half that of the

This is all really just theory, but it does pretty closely fit with the known facts and details from Sunamp, and the experience of Jonathan Porterfield up in Orkney.  Why else would Sunamp have reduced the maximum pressure permitted, and added these over-pressure mitigation devices, if it wasn't because over-pressure can cause issues like this?

Hello @Jeremy Harris, welcome back. I thought of Jonathan’s video as I was reading the first post. I have taken so long with my build that I think there have been two iterations of the Sunamp whilst I have been building. I now have a Sunamp Thermino 300 ePlus in my plant room waiting for me to plump it in. 

Edited 19 hours ago by Nick Laslett

[Jeremy Harris]

12 minutes ago, Nick Laslett said:

Hello @Jeremy Harris, welcome back. I thought of Jonathan’s video as I was reading the first post. I have taken so long with my build that I think there have been two iterations of the Sunamp whilst I have been building. I now have a Sunamp Thermino 300 ePlus in my plant room waiting for me to plump it in. 

 

 

Thanks for the kind words (and to everyone else that's said similar).  I'm reasonably confident that Sunamp are on top of this, if I wasn't, then I'd not have still been of a mind to buy another (before Sunamp agreed with the warranty thing). 

 

My view is that they have been going up a learning curve with these things, and, from what I've seen since 2016, when I first got involved with them, their technical approach has always been very good.  The original Sunamp PV, for example, was technically a bit over-engineered.  It was a complex solution to the challenge of evenly heating the PCM, using the same heat exchanger used to get the heat out to put the heat in, via multiple non-return valves, a variable speed pump and an inline electric heater.  The thing was, if anything, too clever for its own good (although I still have the view that it was the best way to produce a more or less infinitely repairable unit!).  It must have cost a fortune to manufacture though, given all the parts it had.

 

If I had to guess, I'd say the primary cause of the early UniQ issues related to the switch to embedded electric heating elements and controls that were not really well-optimised for efficient charging from PV.  This had been the unique selling point for the Sunamp PV, and the reason I was so enthusiastic about it, it was, as its name suggests, optimised for utilising excess PV generation (and it was very good at it indeed). What I'd not realised was that they had looked at the market and realised that it was a LOT broader than just people looking to make best use of their solar panels. 

 

They may even have been a bit prescient, and guessed that export payments might increase (now up to around 15p per kWh payment on some tariffs) and realised that this might kill off those looking to utilise spare PV generation for water heating.  TBH, if we were able to have a smart meter (we can't - not enough signal here)  then I'd not bother with using PV to heat the water, it'd be better value to sell any excess at 15p/kWh and then buy in off-peak at around half that price to heat the water.

 

We have a heat pump, used solely for running the UFH and pre-heating the supply to the Sunamp (via a plate heat exchanger inline with the inlet) and it simply doesn't make sense to run that at the 65°C required to charge a Sunamp via hot water, as the COP is absolutely appalling at that flow temperature, especially in very cold weather.  This is pretty much what convinced me to go down the path of an electrically heated hot water system, that could be heated in winter using cheap off-peak electricity (currently 6.308p/kWh on an SVR E7 tariff), and also use excess PV when that was available.  Not a one-size-fits-all solution at all, but one that seems to fit well with our needs.

 

Overall, I've always been impressed with the performance of the Sunamp.  Having oodles of hot water on tap and just never having to even think about whether there is any need to be a bit careful with it is a lot less hassle.  For years it has just sat there doing its thing with zero attention from me.  About the only thing I do is glance at the Home Assistant screen each day to see how much energy we've used heating the water, and that's really only a casual interest thing (like noticing we've used an extra kWh of hot water because my wife's washed her hair . . . ).

[TerryE]

@Jeremy Harris, really nice to hear from you again.  Please keep in contact.   You've been missed.  You seemed to pretty much to have removed your Internet footprint, especially with the lapsing of the mayfly domain.  I once did have a search and I found an email contact some in some other context, but decided not use it in the end, since I figured that this would be intruding on your privacy.  Anyway back to SunAmps.

 

As Mike said, in the end I gave up on them, and have posted on this journey on several topics.  In terms of replacement, I went for a decent OSO 250L UVC (immersion only).  This has a cylindrical vacuum panel jacket similar to that used in the SumAmps.  The daily parasitic heal loss is somewhere between 1-1½ kWh; this only about 30% more than my 2 SunAmp PVs.  Not enough to cause overheating, and this does ultimately heat the house at a CoP of 1 anyway.  I have top and bottom digital thermos and once a day my control system uses their readings to estimate the top-up heat required to bring the UVC back up to temperature.  I then schedule heating for least-cost on my Octopus Agile tariff so most days the cost of H/W is around 20-50 p, and often less.   This all works well, and we've never regretted the switch.

 

Now lessons from the tear-down of the defunct SunAmps: 10/10 for the concept; 2/10 for controller board design and implementation; 5/10 for the mechanical implementation, but overall I don't think they were engineered for a 10 =-year life let alone something longer.  The form factor also encourages supplier lock-in. 

• They were still using the same controller board until recently for the UNIQ series.  They were really terribly electrically, thermally, etc. Just nowhere near what I'd expect on a product at this price. I was replacing one every 2-3 years.    I can go into more details if you want.  I had one of the thermometers fail as well
• In terms of plumbing construction, the PVs were a nightmare, in that they were practically unmaintainable in-situ. When I did the tear-down, just too many joints were weeping and showing bad corrosion.  Clearly there was steady dripping into the internals in one unit.  This might have been addressed in the Uniq units.  However note that @Nickfromwales and others that reported issues with the internal cell immersion heaters for the electrical boost  option: these aren't a replaceable component. The only practical option is a complete cell swap and this isn't a field-repair option either.
• One of the 4 PC cells showed evidence of internal corrosion on the internal copper at a solder joint. If this went then this would have let the potable water bleed into the salt chamber and ultimately caused the sort of failure that you experienced.

So IMO, if you do do a SunAmp swap then you should anticipate a similar life of under 10 years for the replacement unit.  

 

Edited 17 hours ago by TerryE

[Jeremy Harris]

34 minutes ago, TerryE said:

@Jeremy Harris, really nice to hear from you again.  Please keep in contact.   You've been missed.  You seemed to pretty much to have removed your Internet footprint, especially with the lapsing of the mayfly domain.  I once did have a search and I found an email contact some in some other context, but decided not use it in the end, since I figured that this would be intruding on your privacy.  Anyway back to SunAmps.

 

As Mike said, in the end I gave up on them, and have posted on this journey on several topics.  In terms of replacement, I went for a decent OSO 250L UVC (immersion only).  This has a cylindrical vacuum panel jacket similar to that used in the SumAmps.  The daily parasitic heal loss is somewhere between 1-1½ kWh; this only about 30% more than my 2 SunAmp PVs.  Not enough to cause overheating, and this does to heat the house at a CoP of 1 anyway.  I have top and bottom digital thermos and once a day I use there to estimate the top-up heat required to bring the UVC back up to temperature.  I then schedule heating for least-cost on my Octopus Agile tariff so most days the cost of H/W is around 20-50 p, and often less.   This all works well and we've never regretted the switch.

 

Now lessons from the tear-down of the defunct SunAmps: 10/10 for the concept; 2/10 for controller board design and implementation; 5/10 for the mechanical implementation, but overall I don't think they were engineered for a 10 =-year life let alone something longer.  The form factor also encourages supplier lock-in. 

• They were still using the same controller board until recently for the UNIQ series.  They were really terribly electrically, thermally, etc. Just nowhere near what I'd expect on a product at this price. I was replacing one every 2-3 years.    I can go into more details if you want.  I had one of the thermometers fail as well
• In terms of plumbing construction, the PVs were a nightmare, in that they were practically unmaintainable in-situ. When I did the tear-down, just too many joints were weeping and showing bad corrosion.  Clearly there was steady dripping into the internals in one unit.  This might have been addressed in the Uniq units.  However note that @Nickfromwales and others that reported issues with the internal cell immersion heaters for the electrical boost  option: these aren't a replaceable component. They only practical option is a complete cell swap and this isn't a field-repair option either.
• One of the 4 PC cells showed evidence of internal corrosion on the internal copper at a solder joint. If this went then this would have let the potable water bleed into the salt chamber and ultimately caused the sort of failure that you experienced.

So IMO, if you do do a SunAmp swap then you should anticipate a similar life of under 10 years for the replacement unit.  

 

 

Many thanks, Terry, that's very helpful and fills in a few gaps that I had sort of guessed at.    I am near-certain that our failure is from a leak having developed internally in the heat exchanger, that has allowed water to pressurise the PCM cell.  The PCM has then burst out of the cell (not 100% sure where, but I suspect either the pipe entry points or the fill port) causing the leakage I've experienced.

 

One slight puzzle is that the leakage on ours self-healed.  Despite having a pretty constant 3 bar of water pressure in the heat exchangers there was no further leakage.  I can only assume that the PCM froze around the leak and sealed it up, although I'd have thought that, given the solubility of sodium acetate trihydrate in water, this wouldn't have been that likely.  Perhaps it may have been that as the internal temperature dropped the leak sealed itself up a bit.  All a bit unknown, really.

 

I did think long and hard about replacing it with a UVC.  Main problem is that I really don't have enough room, now.  The services area has filled with stuff, and my only option would have been to try and squeeze in a very slim cylinder, but even that would have needed a lot of stuff to be relocated, at least a couple of days work, on top of installing the UVC.  This all stems from having made decisions around the use of a Sunamp, right back in 2016!

 

Sunamp seem committed to their ten year warranty for the PCM cell and heating elements, which is very reassuring.  I'm tempted to fit a back up hot water option, though, just in case, and have been looking at some of the smaller, wall-hung, water heaters.  They almost certainly wouldn't be a good option for all our hot water, but having something to fall back on that could provide a couple of quick showers a day would, right now, look like an attractive option!

 

Sorry about the domain, thing, leaving the EU cancelled my .eu domain, so it stopped working.  Finger trouble on my part meant that I screwed up the transfer to a new .uk domain and lost everything, which was a pain, but unlike you I'm very much an amateur when it comes to IT!

[Stones]

Welcome back @Jeremy Harris, good to hear from you. Funnily enough saw your name last week on recent posts on a forum about VOIP telephony.

 

Really good to hear Sunamp are stepping up.  Hopefully the decoration side and tidy up won't be too onerous (insurance claim?)

 

I certainly looked long and hard at the Sunamp back in 2016, but in the end went with an ASHP and 300 litre UVC set up for a number of reasons, one of which was wondering what future support would look like given our location.  The ASHP / UVC set up has worked really well, but I was fortunate in having the space to make that decision.

[MikeSharp01]

@Jeremy Harris Can I ask a question about your SAP? Many on here have real issues with SAP not allowing a high rating if you have direct electric heating of DHW. Your set up does have this in effect, with some PV, but I guess that your SAP was worked out on your ASHP. Have I got that right?

[TerryE]

I assumed that the PCM salt would be soluble in water.  I found this not to be the case once the salt had changed into the solid crystal phase.  

[Jeremy Harris]

6 minutes ago, Stones said:

Welcome back @Jeremy Harris, good to hear from you. Funnily enough saw your name last week on recent posts on a forum about VOIP telephony.

 

Really good to hear Sunamp are stepping up.  Hopefully the decoration side and tidy up won't be too onerous (insurance claim?)

 

I certainly looked long and hard at the Sunamp back in 2016, but in the end went with an ASHP and 300 litre UVC set up for a number of reasons, one of which was wondering what future support would look like given our location.  The ASHP / UVC set up has worked really well, but I was fortunate in having the space to make that decision.

 

Thanks Jason, the VOIP thing was me working out how to retain a working landline here, and getting a backup for when the power fails and our fibre cabinet falls over (as it still seems to).  When the PSTN gets turned off later this year we risk being left without a reliable phone, and I wanted to jump the gun and get something tested and working before that happens.  It does work, too, using a Mikrotik high gain dish antenna/router, a Grandstream VOIP adapter and a cheap account with Andrews and Arnold (who I'd very much recommend).  We now have a working fall back "landline" phone that carries on working when storms take the power out, which is useful.  Part of that is that we now have 22kWh of battery storage, that keeps the house going for a fair old time if there's a power cut.

 

In some ways I wish that I'd kept enough free space for a UVC, but a large part of me wants the Sunamp to be the answer, mostly because, despite some of the issues, I still think the basic technology is sound.  The fact that it's worked flawlessly, and very economically, from 2018 to last Saturday also makes me think it's worth sticking with.  I do have a fall back plan that I've now written down, so someone could implement it if I'm not able to, which would allow a slimline UVC to fit, albeit with a lot of work.

[Jeremy Harris]

6 minutes ago, MikeSharp01 said:

@Jeremy Harris Can I ask a question about your SAP? Many on here have real issues with SAP not allowing a high rating if you have direct electric heating of DHW. Your set up does have this in effect, with some PV, but I guess that your SAP was worked out on your ASHP. Have I got that right?

 

 

No, the SAp was done with direct electric heating for hot water, as that was always the plan, initially with a thermal store, which then got swapped out for the Sunamp.  We did take a hit for using direct electric heating for hot water, but it wasn't massive, but then our SAP was done using the 2012 version, IIRC, and things may well have changed since then.

[Nickfromwales]

3 hours ago, Jeremy Harris said:

 

Wasn't it @Andy T who had the same problem with his Sunamp?  IIRC it leaked all over the floor of his conservatory.  His will have been an earlier model of mine, as I think he had it as some sort of trial, much as I did originally.  I think it may have been some sort of special, too, perhaps one of the PCM34 models that got dropped eventually.  I remember seeing a photo of the goop all over his floor, if it is the same person.  I met him face to face at the Swindon self build centre, some time after I'd installed the Sunamp, as I remember having problems with the charge points there, which will have been when I had the little BMW i3.

Hi @Jeremy Harris, welcome back and sorry to hear it's not under slightly better circumstances! Great to 'see' you none the less, and I sincerely hope you are well.

 

I have quite a bit to contribute, just have to go sort a few things for the home first, get myself behind the keyboard, and then I'll add what I know and a few extra bits for good measure; facts and sense only of course, but you're just another who is now on the list of "folk with salty ceilings" (and floors).... 

[TerryE]

@MikeSharp01, this is an artefact of SAP rather than a real issue.   Last night we used 2.3 kWh heating our after back to target.  We've got a bit of a Dunkelflaute at the moment so the cheapest was 18.2p so or H/W cost about 42p.  SAP needs fixed not the implementation.

[Jeremy Harris]

7 minutes ago, TerryE said:

I assumed that the PCM salt would be soluble in water.  I found this not to be the case once the salt had changed into the solid crystal phase.  

 

 

Thanks Terry, that's very useful and may well change the way I go about trying to fix the ceiling damage.  I had thought that I might get away with just washing off all the crystals that have blown the paint off, in the hope that the plaster might then dry out and allow the ceiling to be repainted.  I could just make an insurance claim, get that section of the ceiling cut out, all the crystals removed and then patched, and may still do that, it all depends on how things go over the next week, with the replacement.  One thing is for sure, and that is that I am going to add a bund around the replacement Sunamp to try and contain the goo if this should every happen again (and I sincerely hope it does not!).

[MikeSharp01]

Just now, TerryE said:

this is an artefact of SAP rather than a real issue. 

Yes and it needs fixed. 

[Jeremy Harris]

4 minutes ago, Nickfromwales said:

Hi @Jeremy Harris, welcome back and sorry to hear it's not under slightly better circumstances! Great to 'see' you none the less, and I sincerely hope you are well.

 

I have quite a bit to contribute, just have to go sort a few things for the home first, get myself behind the keyboard, and then I'll add what I know and a few extra bits for good measure; facts and sense only of course, but you're just another who is now on the list of "folk with salty ceilings" (and floors).... 

 

 

I had hoped that you might have some words of wisdom, Nick, when I first started this thread, given that you've had a fair bit of experience with these things.  What's not clear to me is just how many units have leaked out their PCM.  I know of two (other than ours), @Andy T and Jonathan Porterfield, but assume there must be more, because Sunamp have clearly made significant changes that seem related to the cause of this issue.

 

Be interested to know if you think that pressure is a contributory cause, given that there seems to be a lot of focus on reducing pressure-related events with the newer units.

[Jeremy Harris]

4 minutes ago, MikeSharp01 said:

Yes and it needs fixed. 

 

IMHO, SAP has always had anomalies that need to be fixed, I think there are probably other threads here where I've highlighted how mad some of the assumptions and calculations it uses are.  Part of me thinks this is just down to it always being out of date, but another part of me always questions the competence of those that create it.

[TerryE]

2 hours ago, Jeremy Harris said:

I had thought that I might get away with just washing off all the crystals that have blown the paint off

Chip off a bit and try to dissolve it. It hardly dissolves in cold water but you can get it to dissolve in boiling.  TBH, I suspect that even with mechanical removal / steam cleaner, it'll be hard to get back to a decent decoration surface. 

 

From the OP, it looks like you've got the edges of 4 or 5 8×4 PB sheets compromised that wont take decoration, so there is quite a lot to take down / replace.  One alternative to stripping out the entire ceiling might be to sand down then put up a second PB layer on top.. 

 

@Nickfromwales, if this is isn't giving recurring nightmares, you might have some remediation suggestions.  

[Nickfromwales]

7 hours ago, Jeremy Harris said:

 

 

I had hoped that you might have some words of wisdom, Nick, when I first started this thread, given that you've had a fair bit of experience with these things.  What's not clear to me is just how many units have leaked out their PCM.  I know of two (other than ours), @Andy T and Jonathan Porterfield, but assume there must be more, because Sunamp have clearly made significant changes that seem related to the cause of this issue.

 

Be interested to know if you think that pressure is a contributory cause, given that there seems to be a lot of focus on reducing pressure-related events with the newer units.

Hi @Jeremy Harris.

 

Firstly, any opinions or information hereby given by myself are my own views, experiences, and knowledge ONLY, and are to be taken as such. I am just a random bloke on the internet. However….the FACTS, ones which I can evidence, are as follows.

 

I know of a number of these units which have forcibly ejected the PCM from the case, however it is purely a matter of my own deduction as to the cause for some, and direct and factual knowledge for others, given whether I was involved directly or indirectly, and whether I had the opportunity to examine the failed unit(s) or not. Also, some I installed and some I simply attended after they failed.

 

Firstly, Jeremy, I do not wish to give you a bum steer here, seeing as it makes sense for you to go KISS and adopt the new unit offered to you currently FOC. Please ask if you require further clarification, as with ALL MEMBERS, by sending me a PM to enquire about my experiences / feedback, and reasons why I would perhaps pursue your other options. FYI, I do have better things to do y’all, so please only PM if maybe you are currently in conflict or suffering difficulties, but I will help members as much as I can (if I can).

 

Perhaps @readiescards can enlighten us as to whether SA compensated him for property damage, when his units failed at his rental property. If so, then I assume they would meet your costs, @Jeremy Harris, for repairs to your home too.

 

An architect I know suffered the same fate as you Jeremy, in their new home, as did someone aforementioned in this thread (someone who was on their 7th replacement SA unit before turning his back on their final offering, understandably then favouring an UVC which to date AFAIK has not flooded his home, unlike the SA’s). I can only assume the architect was compensated for his damages, especially with having to move his family and new born baby into a hotel for a week or two; that unit also leaked from a 1st floor airing cupboard and molten PCM made its way all through the hall/stairs/landing etc wiping out the house electrical system as it went.

 

The title of this thread says “catastrophic”, which I heard a lot from folk where these things had gone, often spectacularly, wrong. Some of these instances are documented on Buildhub, pre-covid, IIRC, on public forum. I can throw up some links if anyone is interested, searching is relatively easy though for anyone who cares to investigate for their own satisfaction. The biggest kick in the bollocks is where these are the customers only means of obtaining hot water.

 

To date I can recall only 3 ‘catastrophic’ UVC failures in over 30 years in the trade, all due to negligence or ignorance from either the owner or the installer. Only one was due to the actual cylinder failing, and that was a POS Ariston (glass lined) one where the sacrificial magnesium anode had not been replaced.

 

To date, the number of failed SA units I alone have dealt with / been associated with is in double-digits; the first number is not a 1. That’s just me, a non-registered installer (I was never ‘registered’ per-se but I was drafted by them and became the 1st SA installer in the UK, outside of SA that is, employed indirectly by themselves in that capacity for nearly 2 years), and the majority of my association was not as a new installer but by being a repair or replacement agent, often under duress. During that period, and then beyond, I visited various units ranging from the early version of the Sunamp PV, all the way through to the units that preceded the “Thermino” range; the latest version of the UniQ, which had the onboard electronics vs the large wall mounted controller.

 

Again, for completeness, I have zero association or experience with the newest Thermino range, but my own opinion there is that it is very much the same box which the sales & marketing team have given a new name, perhaps simply to disassociate the new product from the muddied reputation of its predecessor. Sunamp, Thermino and Aquafficient (AFAIK) are the same product from the same source.

 

Having been left at the frontline with several disgruntled customers my love of these things quickly diminished, but, for clarity and completeness, up until this point I thought these things were ‘the future’ and I was a huge advocate of them. I genuinely thought they were the mutts nuts; more so when they were actually affordable in comparison to a quality UVC! Currently, as Jeremy states earlier, the pricing of these for supply & fit via their ‘trusted partners’ is now just completely insane, however there is no law against overcharging unfortunately.

 

I can evidence instances where SA refused warranty claims, until I got involved and supported the claimant in their representations. Miraculously, once I got involved, free units were then immediately doled out (supplied and fitted free of charge)…. In most instances initially SA refused to honour the warranty claiming the units had been fitted in a “non-standard” way. It was a little embarrassing for SA when I told them that @readiescards refusal could not possibly be upheld; seeing that I worked closely with SA to pioneer one of the few dual SA low & hi temp installs in the UK at his property and Sunamp had endorsed and approved directly my own design for his installation, scrutinised and approved by the man in charge himself no less. Odd that they forgot about this, when first approached by the client independently.

 

“Well done Sunamp”, my arse.

 

@Jeremy Harris, I wonder if you could clarify if it was after this thread was posted that you got your offer of the replacement? Feel free to ignore this question, it is purely for my own curiosity, but it would be refreshing to hear that this was a genuine olive branch that you were offered with some signs of sincerity…

 

Anyhoo…..I think you all get the idea of my position, so let’s get to the burning question: “Why do these things keep going pop?”.

 

The answer, not only in my opinion but also from first hand experience, is systemic bean-counting in the manufacturing processes, plus the dismissal of mine and former SA employees suggestions for making these things more robust. The top line obviously came above everything else.

 

These things were first put together rather clumsily, and the tour of their manufacturing facility back then was ‘interesting’.

 

SA PV’s just choked up with limescale due to the tiny micro bore pipework in the HEx, and the cheap option “water conditioners” recommended to the customers were not even touching the sides of combatting scale etc. If you live in anything resembling hard water, you will need a full-on water softener to stand a chance here, but all I found were plug-in bits of crap with a clamp on the pipe performing miracles, or not. The amount of crud that I got out of one SA PV in the Forest of Dean was clearly the cause of that lady having no hot water (or resolution) for 13 weeks or so, which is how long she was given either excuses or zero communication for. You could understand if this was a one-man band, but not what you’d expect from a company of that size / structure, absolutely terrible.

 

Things seemed to worsen with the advent of the UniQ, IMO, where these would often swell up with overheating of the PCM to the point where the lids were bulging 75mm upwards, and the forces thereof were enough to snap the M5 Allen head bolts off that held the lids on. That and cheap overheat stats keeping tripping out rendering the unit dead. Pics of those still provoke gasps, as you need to see it to actually believe it.

 

Most would jump to the assumption that the incoming cold mains pressure had compromised the SA HEx, but no. To this date, I know of not a single unit that had a failure that had potable water constantly leaking from the HEx. Let’s be Sherlock Holmes for a moment, “Fetch my pipe, my dear Watson, we may be here a while…”.

 

Mains pressure leaking from an instantaneous water heaters HEx (heat exchanger) would result in a flooding of a property where you needed wellies. This type of failure would result in a constant flow of water coming out at mains pressure, until discovered, and then the mains being switched off to prevent the 10’s or 100’s or 1000’s of litres of water, or more, being lost. In a nutshell, If it was a cold mains related failure, you’d bloody well know about it.

 

These instances seem to recount my experiences, eg where the units puke out the excess PCM due to it ‘going nuclear’ and the only damage / evidence is the small-ish volume of molten salty yogurt making its way through the fabric of the building (vs constant running cold water flooding out everywhere). Jeremy says in his instance this may be because the PCM sealed the leak, but me, personally, I doubt the PCM could ever hold back static cold mains pressure, and even less where there would be a path already created from the hypothetical hole in the HEx, carved by the molten PCM, to atmosphere.

 

The issue actually was / maybe still is (admitted to me directly by an ex Technical rep at SA) that the thermistor string that resides vertically in the core was ‘on the move’. Curious of this explanation, whilst stood in front of another trio of failed units in one home and yanking my hair out in despair, I checked the validity of this information / theory. It seemed kosher as the thermistor string was only held in place by gravity plus an ill-fitting compression cable entry gland (I’ll post the pics of these parts when I can find my other iPad) which seemed completely incapable of doing its job; the gland couldn’t close down tight enough at its max excursion so was pointless / useless. This chap was clearly a clever lad and had looked into this with vigour, arriving at this conclusion from (I assume) multiples of other similar instances of failure which forced him to surmise. Saved me a lot of looking / testing / time wasting because he was spot on! Shame he’s not there any more, but SA had difficulty holding onto good people, particularly those who had an opinion.

 

So, to explain what was happening, the PCM would ‘flex’ slightly during heat / cool cycling and this created physical movement within the core of the cell. There was a flimsy tube set into the centre of the PCM core, which allowed the thermistor string to be pushed downwards into it, and each heat / cool event seemed to be creating a little movement which somehow squeezed or otherwise manipulated the tube which translated into the upwards migration of the lowest thermistor of the string. This could very well have been happening maybe by only 10th’s or 100th’s of a mm a time, but that marked the beginning of the end. As the immersion heater is installed at the very bottom of these things, and the electronics that switch 230v power to the immersion on / off rely on feedback from the thermistor string, as the lowest thermistor creeps away from the heat source that provides the temp reference the longer the immersion stays on and the hotter the PCM becomes. This continues from bad, to worse, right through to ‘salty ceiling mode’ kicking in.

 

Basically the immersion was then staying on way past the point that the PCM melt-point required, which then led to the PCM58 effectively boiling (I think it did that at around 85º) and there’s the source of your salt-puking problem. The PCM cell is a sealed unit and comes factory fitted with its own internal ‘PCM PRV’ which opens to allow the PCM to escape when over pressure is terminal, eg to allow it to go ‘POP’ and stop it going ‘BANG’.

 

The aforementioned project where 3 units failed in a few months was painful to be around / associated with, as SA paid me to go and replace them with these “new” UniQ’s (with the onboard electronics) and I thought “phew, now time to pack my shit up and go home again” as I was confident these new units would be “all sorted”….. “Nope”, and back I went, again, to be screamed at again.

 

The point being, these people did not listen, or learn. My new found confidence at the arrival of these replacement units was short lived, as when I returned back to this site and opened up the first of the then failed replacements (yes that’s right) I couldn’t believe what I was looking at. The build quality was horrific, cable management was not just rough as a badgers arse but also (IMO) dangerous, with single PVC 230v cables not in containment or grommeted and more. I have MANY pictures should anyone think I am just a raging buffoon or a liar. No wonder they didn’t last very long…..

 

That’s where my SA adventure ended. Hello UVC, I’ll never be unfaithful to you ever again.

 

So, on to the next issues…. These things were sold as not needing G3 certification, “requiring no expensive annual maintenance or inspection” and so on, but I’m not sure what the advice (instructions) from SA is these days. If anyone could post here to clarify, eg if this is now superseded by a new sales patter (stated in black & white that G3 is now needed or not needed) as this may now have changed, that would be nice to hear about.

 

I had always been sceptical of this ‘no G3 etc’ claim as the units all require expansion vessels, these are supplied by SA and their inclusion is stipulated in the SA MI’s. Mentioned previously in this thread is an instance where someone mentions possibly a unit failure being attributed to the EV being spent and ineffective; I’d look into this though, as if you’re not told to check these in the MI’s then why would (should) you be accountable for this item then failing and you then being incorrectly or unfairly deemed “out of warranty” and left to foot the bill?!? That’s negligence in my books.

 

I think this suggested lack of requirement for service / maintenance was total sales BS, yet it made for an excellent USP.

*Has anyone reading this been told of any annual service requirement for a Thermino or Aquafficient? Please say now, or forever hold my piece*.

 

As with any EV, the one fitted mandatorily to every SA unit surely has to be commissioned to match the back-pressure pre-charge according to the incoming mains water pressure, for every single unique instance / install, and this then can only be proven to be doing its job of protecting the unit IF IT IS INSPECTED AND CHECKED FREQUENTLY. This periodic service / inspection protects against a failed EV unit being inadvertently left in commission, for one, but also allows for changes to be made to these values downstream eg if the street (network) pressure at the dwelling has changed since the unit was 1st installed, aka “good practice”.

 

Now we come to the cherry on the G3 cake.

 

So…..NOW you have to install a control group to a SA unit (a combination of valves that provide incoming cold mains pressure reduction and pressure relief (discharge)) a-la an UVC install which requires annual inspection to check these safety devices are in good order / functioning correctly etc, BUT, does the new SA MI state that you need to prevent over pressure from mixing taps if this is a replacement or retro-fit instance? Because if the pressure reducing valve is only at the SA cold inlet at the device, then the network cold mains pressure will simply bypass this (by reverse pressurisation through back-flow from showers / thermostatic valves / mixer taps and so on) and render all that completely useless eg a total waste of time and effort.

 

No mention in the new SA Thermino MI’s about the pressure relief valve being a D1 or D2 discharge and how it should be installed / terminated / pipe size charts etc? Just say's, from what I can find online, to fit a 6 bar PRV with no mention of what happens when that opens!! Surely if a PRV can be discharging potable water to a drain for the rest of time, if unnoticed, it should then be governed eg fits into G3 categorisation?

 

What a mess…