SUNAMP ISSUES

[Simon Brooke]

Hi, We are two weeks into the new house . Generally pretty happy but one or two issues arising. One is our Sunamp, a Uniq edual 9kw. This was bought to provide underfloor heating and hot water. We had hoped to use PV excess and top up with economy 7. Yesterday was very dull, though not overly cold, and we used the underfloor to raise the temp. from 16 to 19 degrees. We have the manifold mixing valve set at about 35 degrees. Basically, it struggled and eventually used all its capacity (indicated by no hot water). As an aside I really hate not being able to see what the level of capacity is. Anyway, it then spent the rest of the day clicking every couple of minutes as though it was switching on to charge. Eventually I put it on to boost for an hour but this didn't help. Overnight it seemed to charge because when I put it onto boost it (eddi) showed max temp reached which I interpret as battery at full capacity. The clicking noise is still continuing AND no hot water. Any thoughts before I try to ring Sunamp tomorrow? Many thanks,

Simon

Edited January 26, 2020 by Nickfromwales
PV

[Jeremy Harris]

The clicking noise is most probably the relay turning on and off when the unit is in cold start mode.  It needs to be continuously powered to complete the cold start cycle, as it pulses power on and off to the heating element in order to melt the solid PCM around it without risk of overheating.

 

Once the temperature at the base of the unit is high enough to indicate to the control unit that the PCM around the element has all melted, the unit will keep the heating element on until the unit is fully charged.

 

There are other clues to listen for.  When doing a cold start there will be a crackling noise, a bit like a crushed up crisp packet, whilst the heating element is on.  If you are not hearing this, and the unit is staying in cold start mode, then this indicates that the heating element is not getting hot.

 

There are two things to check, as this exact problem happened with our unit.  Firstly, check that the over-temperature cut out hasn't tripped.  Isolate the power, test to make sure the power is off, and then unscrew the cover at the left side of the unit at the bottom.  Behind this are the connections to the heating element, and at the far left of the opening there is a reset button.  If this clicks when pressed in, then it has tripped.

 

The other failure mode (and the one we experienced) is the contactor in the control box.  If your unit has a Finder contactor at the lower right side of the DIN rail inside the control box there there is a chance this has failed.  When ours failed it was still clicking on and off, but the contacts were stuck open.  I replaced it with an ABB single module 20 A contactor that I happened to have in stock and the unit came back to life.  At the time, Sunamp were just not responding to complaints, and didn't even acknowledge this failure, let alone do anything about it.  Our unit was about 3 months old when the Finder contactor failed.

 

Sunamp have since changed the design of the control unit, and after much badgering they supplied me with a complete new control box.  I noted that this new control box has a different type of power relay, so my guess is that they may know full well about the poor reliability of the Finder units.

 

If you get stuck, and find that it is the contactor that has failed, then I'm not far from Somerset and I still have the ABB contactor I used to fix our old control box.

[Simon Brooke]

Many thanks for the info and kind offer. Apart from my lack of electrical skills, I have a SMALL problem in that I have put the sunamp neatly in a left hand corner and then covered it with a lovely piece of work top! I knew I would pay for being neat.  Have put on boost again with,sadly, no crisp packets and no warm water. I will see if I can get any sense out of Sunamp tomorrow before opening up the control box to see what type of switch is there. Thanks again.

Simon

[Jeremy Harris]

35 minutes ago, Simon Brooke said:

Many thanks for the info and kind offer. Apart from my lack of electrical skills, I have a SMALL problem in that I have put the sunamp neatly in a left hand corner and then covered it with a lovely piece of work top! I knew I would pay for being neat.  Have put on boost again with,sadly, no crisp packets and no warm water. I will see if I can get any sense out of Sunamp tomorrow before opening up the control box to see what type of switch is there. Thanks again.

Simon

 

If you open up the control box and it is the version with the Finder contactor at the lower right corner, then if you have a meter you can check whether the contactor is actually working by checking to see if there is power on the two terminals at the bottom, should be marked 2 and 4, when the contactor is on.  If there is power on those two terminals, going on and off as the contactor clicks, then the problem is most probably downstream of there, either the heating element, the over-temperature cut-out or perhaps a wiring problem.

 

This is a photo I've just taken of our old control box, with the ABB contactor that I fitted to replace the faulty Finder one.  It's probably a slightly different layout to yours, but I'm pretty sure they all have the contactor/relay at the lower right side:

 

[Russdl]

I'm following with interest as always, but I guess this:

 

52 minutes ago, Simon Brooke said:

I have a SMALL problem in that I have put the sunamp neatly in a left hand corner and then covered it with a lovely piece of work top!

 

Will prevent @Simon Brooke doing this:

 

4 minutes ago, Jeremy Harris said:

This is a photo I've just taken of our old control box, with the ABB contactor that I fitted to replace the faulty Finder one

 

Thank's for your continued Sunamp research on our behalf @Jeremy Harris

[Ed Davies]

@Simon Brooke, do you have a separate control unit or one of the newer Sunamps with the control unit in main box?

[Nickfromwales]

If the UFH is calling for heat then the SA will NEVER heat up as it’s likely the demand is equal to, or greater than, the energy input ( output ) that the 3kW immersion can provide. 
Turn off the UFH and hit the boost for 2 hours. Run a hot tap and see if you get heat. 

Do that and reply here please. 

Also, how old is the unit? When was it delivered? Also when did you get the Eddi? They now have a ‘Sunamp’ setting which ignores the chunked energy consumption during cold start and therefore does not prematurely show as ‘max temp reached’   The issues may be multi-fold here, as differing periods of manufacture will have dictated which iterations you have to ‘problem solve’. 
Also, IIRC, the latest SA does not do cold start now as they’ve determined that putting the immersion on flat out from cold doesn’t damage the local PCM as they first feared.

More info required, most importantly which SA unit you have and do you have the latest logic on the Eddi. 
 

[Jeremy Harris]

10 minutes ago, Nickfromwales said:

If the UFH is calling for heat then the SA will NEVER heat up as it’s likely the demand is equal to, or greater than, the energy input ( output ) that the 3kW immersion can provide. 
Turn off the UFH and hit the boost for 2 hours. Run a hot tap and see if you get heat. 

Do that and reply here please. 

Also, how old is the unit? When was it delivered? Also when did you get the Eddi? They now have a ‘Sunamp’ setting which ignores the chunked energy consumption during cold start and therefore does not prematurely show as ‘max temp reached’   The issues may be multi-fold here, as differing periods of manufacture will have dictated which iterations you have to ‘problem solve’. 
Also, IIRC, the latest SA does not do cold start now as they’ve determined that putting the immersion on flat out from cold doesn’t damage the local PCM as they first feared.

More info required, most importantly which SA unit you have and do you have the latest logic on the Eddi. 
 

 

 

Nick, from the description given, the Sunamp is powered up and seems to be stuck in cold start mode, with the contactor clicking on and off, but the heating element not actually heating the PCM.

 

I don't think this can be related to the Eddi or the UFH, if the Sunamp is just stuck for hours in what sounds to me like cold start mode, especially as it's being powered by being switched to boost mode, which should just apply power to the Sunamp, regardless of any other settings. 

 

This is identical to the symptoms we had when the Finder contactor failed, and Simon's units is a similar vintage to ours, I think.  The unit just sat there clicking the contactor "on" and off, but no power was getting to the heating element.  Given that there's also no "crunching crisp packet" sounds from the Sunamp, it seems very much as if there's no power getting to the heating element.

 

 

[Simon Brooke]

Thanks everyone for your responses. The sunamp was purchased June 2018 and is a UniQ eDual9. The Eddi came in June 2019 and has a model no. of 16A1P01. The underfloor has not been on when trying the boost mode. I have now noticed that there is an inspection plate at the bottom right of the box so will have a look inside tomorrow.

I have a separate control box which , from memory, looks identical to photo provided by Jeremy.

[Jeremy Harris]

7 minutes ago, Simon Brooke said:

Thanks everyone for your responses. The sunamp was purchased June 2018 and is a UniQ eDual9. The Eddi came in June 2019 and has a model no. of 16A1P01. The underfloor has not been on when trying the boost mode. I have now noticed that there is an inspection plate at the bottom right of the box so will have a look inside tomorrow.

I have a separate control box which , from memory, looks identical to photo provided by Jeremy.

 

 

Your unit will be near-identical to mine, as I thought it was the same vintage, just from the description you gave.  The eDual has slight differences inside the control box, but your description of the fault sounds identical to the fault we had around this time last year.  I'm also near-certain that your control box will have the same Finder contactor as was in ours.

[Barney12]

Might be worth dialling this back a bit. How big is you house (m2) and what is it’s energy requirement?

 

[Nickfromwales]

15 hours ago, Simon Brooke said:

Thanks everyone for your responses. The sunamp was purchased June 2018 and is a UniQ eDual9. The Eddi came in June 2019 and has a model no. of 16A1P01. The underfloor has not been on when trying the boost mode. I have now noticed that there is an inspection plate at the bottom right of the box so will have a look inside tomorrow.

I have a separate control box which , from memory, looks identical to photo provided by Jeremy.

Ok thanks. 
You’ll be on the model with cold start and also possibly a victim of the ( then not very reliable ) overheat stat nuisance tripping. 
I fitted quite a few where the stat would trip a number of times before I could get them to come on ( and stay on ). Often meant extended stays to babysit them through the initial heat up. They’d weirdly work ok after a number of resets ( 4+ resets in some instances ) but I believe the stats then fitted have been superseded by a new / different part to make the current iteration very reliable.

 

12 hours ago, Barney12 said:

Might be worth dialling this back a bit. How big is you house (m2) and what is it’s energy requirement?

 

Deffo. 
Yours struggled on 2x 9’s and got bumped up to 12’s. IIRC you’re still having an issue with one of the stats nuisance tripping?

The Achilles heel with the SA is the 3kW immersion heater. That’s why if there is any sign of duress I’ll fit 2x units ( or 3 ) to get the necessary increase in kWh of input energy. If the dwelling has peak heat requirement of say 4kWh, and you have 2 units so 6kW of immersion, then you’ll have 2kWh of energy available to sustain heat capacity / offset hot water consumption which is meagre on a good day. 
Having been advised to fit a single size9 eDual for this dwelling is a non-starter. You need a LOT of capacity to mix the two services into one unit. I only fit duals now if there is an external high power heat source ( gas / electric etc ) boiler etc. 
Was the intention to load shift off economy rate electricity and fortify with PV? Would be ok in the summer when the heat demand dies off, but for the depths of winter you will seriously struggle here with one unit and only 3kWh to inject at any given time. 

[Jeremy Harris]

18 minutes ago, Nickfromwales said:

Ok thanks. 
You’ll be on the model with cold start and also possibly a victim of the ( then not very reliable ) overheat stat nuisance tripping. 
I fitted quite a few where the stat would trip a number of times before I could get them to come on ( and stay on ). Often meant extended stays to babysit them through the initial heat up. They’d weirdly work ok after a number of resets ( 4+ resets in some instances ) but I believe the stats then fitted have been superseded by a new / different part to make the current iteration very reliable.

 

 

 

Exactly as mentioned in the first reply in this thread, then...

 

 

 

[Simon Brooke]

Thanks again. We have a passive ish house. Passive architect designed and apart from achieving only 1.3 air changes rather than 0.6 all insulation etc is up to design. We were advised that we would need no heating but this in reality seems a pipe dream. It seems we should budget for between 30 and 60 days of dull cold weather. Our current thoughts when we get the Sunamp back up and running is to power up the heating for a couple of hours pre economy 7 cut off and then recharge to full for the day and evening demand.

[Nickfromwales]

Can you get E10 instead so you can chunk heat into the slab outside of typical bathing times ?

That may be possible if you become creatures of habit with when heat is on vs when hot water is needed. 

[Jeremy Harris]

1 hour ago, Simon Brooke said:

Thanks again. We have a passive ish house. Passive architect designed and apart from achieving only 1.3 air changes rather than 0.6 all insulation etc is up to design. We were advised that we would need no heating but this in reality seems a pipe dream. It seems we should budget for between 30 and 60 days of dull cold weather. Our current thoughts when we get the Sunamp back up and running is to power up the heating for a couple of hours pre economy 7 cut off and then recharge to full for the day and evening demand.

 

 

It's a pity that this myth that a passive house will need no heating is still being promulgated.  It was never the case, and the PassivHaus Institut have always allowed for some heating being required in even a certified PassivHaus. 

 

Our's isn't certified, but meets the requirements set by the PHI, yet we very definitely need heating for maybe three to four months of the year.  Not a lot, but the house would be damned cold without it. 

 

We manage to heat the house just using UFH run during the E7 period, and that seems to work fine.  The concrete slab has the UFH pipes set into it, so acts as a giant storage heater.   We only use our 9 kWh Sunamp for hot water, and TBH it wouldn't have enough capacity to be able to do anything else.  There are just the two of us, and we use around 2/3rds of the capacity of the Sunamp each day, just to run showers etc.  If we have guests, we need to boost the Sunamp for an hour or so between showers, in order to give the additional hot water needed.

[JanetE]

Our house is very similar to @Jeremy Harris  up to passiv standard, slightly larger at 210 sqm and with the same slab and underfloor heating.  We have 2 Sunamps which supply our hot water only.  Underfloor is heated using a Willis heater which runs on E7, we have no additional heating upstairs.  We also only need to heat the slab for about four months of the year, but it would get very cold without that input. 

If you want to have a look at our setup, then check out @TerryEs blog.  

[TerryE]

As an addendum to Jan's comment, we have a lot less glass than JSH and so get no material solar gain in the winter months; we also keep our ground floor at around 22-23°C.  Hence we have about 3 months where we need lot of heat input and another 3 months where we need some, though my control system does the heat calcs on a daily basis with all (or the bulk) of heating using the 2.88kW Willis during E7 off-peak, and rarely need heat input beyond this.  We also use the UFH slab as the primary thermal battery. I don't really understand twhat is gained by using a SA as an additional heat battery in series with the slab.

 

[Barney12]

5 hours ago, Nickfromwales said:

Yours struggled on 2x 9’s and got bumped up to 12’s. IIRC you’re still having an issue with one of the stats nuisance tripping?

 

Correct. Its only one of the units and its absolutely when the unit becomes fully discharged. 

 

The official Sunamp fix is (and I quote verbatim)........"turn off the power, remove the front panel and pull a couple of inches of the stat wire out from the housing until you just start to see the curly bit". 

 

EDIT: Sorry, I should have added. I have applied the fix and it stills occasionally trips. Of course because the "fecking great big lump of goopy lard in a white tin box" has absolutely ZERO status feedback you NO IDEA its tripped. Apart from the cold water of course! 

Edited January 27, 2020 by Barney12

[Simon Brooke]

I sent an email to sunamp technical today and chased up by phone to be advised that everyone was in a meeting. When I came in this afternoon Rosie from customer services had rung . She advised that a new battery was being sent to arrive on Wednesday. I explained that it would be very disruptive to change a battery over but she said as it was a self install that was all they could do. I then asked how they knew that it was the battery and not the control unit and explained again what seemed to have happened. She then said we had not had a dual but merely a PV. And I had to explain that the invoice said pv  but was wrongly  labelled. That's it for today as they have to investigate at there end and try to stop the delivery of the wrong battery! I am now going to take the access plate off and have a look for the reset button.

[SteamyTea]

9 minutes ago, Simon Brooke said:

investigate at there end and try to stop the delivery of the wrong battery

So if you have one faulty one, one delivered incorrectly and a proper new one being delivered, can I take the old ones off your hands.

[Simon Brooke]

Sadly, they want the old one back. I have now taken the bottom plate off to reveal a few wires as shown.

[Jeremy Harris]

The thing at the left of the photo is the over-temp cut-out.  If it's tripped then you can tell when you try to reset it by pushing it in, as it will click.  If it doesn't click it hasn't tripped, in which case it seems likely that the Finder contactor in the control box may have failed, as ours did.

 

I had the same problem with Sunamp wanting to send a complete replacement unit.  As ours is upstairs, and a complete nightmare to get up the stairs, I managed to persuade them to just send a replacement control box and sensor string, which seems to have done the job.

[Simon Brooke]

The brown reset button seems to be set, so that is one easy solution ticked off.

[Jeremy Harris]

7 minutes ago, Simon Brooke said:

The brown reset button seems to be set, so that is one easy solution ticked off.

 

 

Whip the lid off the control box and see if your unit has a contactor with the maker's name Finder on it, towards the lower right corner.  If it has, then it's possible that's failed, as ours did.