DIY installation of Sunamp

[Nickfromwales]

18 minutes ago, PeterW said:

No but you can pick one up via Wolesley without an account and they are available online … so they are selling direct via distribution which is what everyone else does. 

But SA are still not selling to the public then. They’re purposefully divorcing themselves from the mammoth number of enquiries and deluges of email regarding their products, and that then falls to the “approved” folk.

[PeterW]

25 minutes ago, Nickfromwales said:

But SA are still not selling to the public then. They’re purposefully divorcing themselves from the mammoth number of enquiries and deluges of email regarding their products, and that then falls to the “approved” folk.

Yeh you can just see the spotty oik on the counter answering technical questions in PlumbCenter..!!  They barely understand the difference between 3/4” and 1/2” 🤣🤣🤣

[Nickfromwales]

You struggle to get discernible answers about gas combi boiler features in the plumbers merchants TBH. Drop the words "phase change material" in and watch the poor buggers melt......   

[MikeSharp01]

7 hours ago, Nickfromwales said:

Installing one is a couple of pipes and an expansion vessel, that's the easy part...........

So what is hard after that? OR is it hard before that?

[Nickfromwales]

11 hours ago, MikeSharp01 said:

So what is hard after that? OR is it hard before that?

Specifying the correct unit for the application is paramount to successful ( and economical ) ownership. Then the type of controls you marry up to it and how you heat and discharge it requires a lot of understanding of how the units 'behaves'.

 

I got called out to a property to see why a SA "approved installer" project was leaving the homeowners without DHW. The capacity was decided at 'size 12' ( aka Thermino 300 ) on paper, but the installer allowed himself to deem it fit to install 2x 6's instead. Same capacity, so what can go wrong? One unit was on grid and the other on excess. Great in the summer, but when PV generation went to the floor they were running on a 6, eg one not huge bath and one shower and zero DHW left. More a problem there with design vs the product itself there, but an example of how ( even at the time when the internal controls were inn play, so not an early unit ) there was still a huge void in the correct design and implementation of these units. Sadly for the homeowner, they ran with this design and finished the house. That meant no opportunity to get electrics and plumbing altered, so both units needed to be changed to a 12 IIRC, ( plus a lot of money ) to resolve . What they should have had was 1x 12 ( core DHW ) + 1x 6 ( pre heat unit on PV ).

The 'problem' is with a SA you cannot add a second immersion and 'super-heat' with PV excess, you can only heat to its stated max PCM temp capacity and no more. An UVC is able to take an additional 30-40+% of 'additional' charge ( dependant on what your minimum / set-back temp is set to ) which makes it great for use as a heat capacitor / battery with zero detriment to longevity. Cost uplift is just the cost of the second heater, and no additional footprint, or major plumbing / electrical works. CONSIDERABLY cheaper option with better results too, imho.

With 400-500% cost increase to consider, its just too expensive a trinket for most now.

[MikeSharp01]

2 hours ago, Nickfromwales said:

Cost uplift is just the cost of the second heater, and no additional footprint, or major plumbing / electrical works. CONSIDERABLY cheaper option with better results too, imho

But not quite fit and forget as you also need to factor in the cost of the annual safety check and, for a highly insulated home, the heat losses - particularly in the summer!  

[Nickfromwales]

1 hour ago, MikeSharp01 said:

But not quite fit and forget as you also need to factor in the cost of the annual safety check and, for a highly insulated home, the heat losses - particularly in the summer!  

A SA relies on an expansion vessel too, and if not regularly inspected and maintained, and it failed causing the SA to fail, you'd be outside the warranty criteria. If you cannot do that test and inspection ( drain down the cold system, read the pressure and adjust / top-u as necessary ) and then refill the system, annually, then you're resigned to paying someone to do that for you, ( so a SA is not "fit and forget" either ).

 

I'm fitting UVC's in highly insulated homes, ( my clients are building all the way from airtight and well insulated, all the way throuhg to one we did recently which exceeded PH certification and attained ZEB credentials ) and, to date, no reports of major side-effects at all. Any issues at yours @ProDave? I design all my clients plant spaces to have MVHR extract point(s), to manage the stagnant heat normally found from the DHW device, but also any other equipment which emits waste / latent heat ( albeit as well as MVHR will allow you to ), and to capture that heat for re-distribution to the house via the HR element of MVHR during winter.

 

In the summer, with the elevated incoming cold mains temps, you can easily revert to a lower set storage temp ( al-a @ProDave and others ) to minimise the impact. Bear in mind also that modern UVC's are VERY well insulated and have quite low standing losses ( around 1-2oC per hour max ) which reduce further when the stored temp is closer to ambient.

@Jeremy Harris only had issues from excess waste heat when he chose a thermal store with an open F&E header tank ( a combination store ) vs an UVC......which he then swapped out to reduce losses.

 

However, I imagine that the annual service ( inspection ) of a SA would be cheaper than a full G3 UVC inspection, but once you ask a professional to attend ( a call out ) then you're already into that fee regardless, so I cannot see the differences ( savings ) being huge. It would be more cost-effective if you had, say, a boiler or an ASHP service person coming out annually anyways and they were asked to check either 'whilst they were there'. I imagine fees would differ dramatically dependant on postcodes. 

[ProDave]

17 minutes ago, Nickfromwales said:

Any issues at yours @ProDave?

None at all.  The HW cylinder is in the spare bedroom that is the smallest of the three and north facing so gets very little solar gain.  There are no issues with the room being too hot, even in summer and arguably the small heat loss is beneficial to an otherwise unheated bedroom in the winter.

 

I am convinced in many installs I see, the vast majority of heat loss is from uninsulated pipes connecting to the cylinder.  It was surprising just how far from the cylinder you have to insulate them properly to keep heat loss down.

[MikeSharp01]

19 minutes ago, ProDave said:

None at all.  The HW cylinder is in the spare bedroom that is the smallest of the three and north facing so gets very little solar gain.  There are no issues with the room being too hot, even in summer and arguably the small heat loss is beneficial to an otherwise unheated bedroom in the winter.

Interesting, the whole choice of DHW has got no simpler since the advent of buildhub or its predecessor!

 

[Nickfromwales]

26 minutes ago, MikeSharp01 said:

Interesting, the whole choice of DHW has got no simpler since the advent of buildhub or its predecessor!

 

Before both I was fitting UVC’s. 
None have ever had a single complaint. 
Since SA………too many to count.

[hotnuts21]

I was considering a SA before reading this thread 🤣 now I'm just confused. 

 

Out of interest @Nickfromwales where abouts in Wales are you based? 

[Nickfromwales]

6 hours ago, hotnuts21 said:

I was considering a SA before reading this thread 🤣 now I'm just confused. 

 

Out of interest @Nickfromwales where abouts in Wales are you based? 

Swansea, when I'm actually in Wales lol.