Sunamp PV - Heating Element

[Novice]

I have 2no Sunamp PVs, installed 2017, they have performed flawlessly, until last Saturday. After a call to Sunamp today and some fault finding with one of their engineers it would appear that the heating element in both units have expired (the joys of living in a extremely hard water area). As there is nobody in the local area (Norfolk) who knows anything about Sunamp PV, I have decided to replace the elements myself. To date Sunamp have not notified me of the specification of the heating element required and cold showers are not great (albeit healthy).

Does anybody know the make/model/spec of heating elements I need?

 

thanks

D

[Dreadnaught]

I have a copy of the 2017 Sunamp manual. Here's (part of) the replaceable parts list. Could it be the "Heater cartridge 2.8 kW x 250 mm"?

 

Message me if you want a copy of the whole manual.

 

[Nickfromwales]

[Nickfromwales]

[Nickfromwales]

 

Phone was not letting me put all pics in one post. 
That’s a replacement one BNIB, that I had off Sunamp when I was replacing these in failed units.
Just checked in packaging and on element itself but no markings / reference sorry.
That’s what it looks like FYI. Hope that helps.  
 

Yellow sleeve just protects the threads in transit.

Edited November 16, 2021 by Nickfromwales

[dpmiller]

What's the thread size and tube diameter @Nickfromwales ? Should be able to hunt it down

[Nickfromwales]

I’ll measure up later, as I’ve just put it back away in the depths of the van aka Aladdins cave. ?  

Ill try it into an 1/2” BSP fitting tomorrow as iirc that’s what it was screwed into. 

Edited November 16, 2021 by Nickfromwales

[ProDave]

28 minutes ago, Nickfromwales said:

 

Phone was not letting me put all pics in one post. 
That’s a replacement one BNIB, that I had off Sunamp when I was replacing these in failed units.
Just checked in packaging and on element itself but no markings / reference sorry.
That’s what it looks like FYI. Hope that helps.  
 

Yellow sleeve just protects the threads in transit.

Just out of interest how do you change these.  They are full of "magic potion" not water.  Does it just work in the principle you only change the heater when it is cold and the potion is in the solid state so it just stays put when you unscrew the heater?

[Dudda]

If you find it can you also post where you found it, any reference code, how you replaced it yourself etc. Any info that you think could help. I've a SunAmp about the same age and I'd have nobody anywhere here either that would know anything about them so will also probably have to do it myself if this fails also.

[Nickfromwales]

1 hour ago, ProDave said:

Just out of interest how do you change these.  They are full of "magic potion" not water.  Does it just work in the principle you only change the heater when it is cold and the potion is in the solid state so it just stays put when you unscrew the heater?

This is a Sunamp PV not an Uniq being discussed. The charge circuit fir the SAPV is a wet heating loop with that little immersion heater in-line. The pump speed was made variable to get the high temp flow up to a point it effectively melted the PCM, but fast enough to not allow it to kettle. The Y strainer which gathered crud in a pot the size of a thimble, and the combination of flow rates / temps / hard water issues saw these “terminally ill” from the get-go sadly, so the softer your water the longer it gets to live. I don’t know of anyone who had routinely serviced this Y strainer, to free it up from crud, but the ones I went out to after they’d failed were blocked solid and had cooked the immersion. Most were replaced FOC with an Uniq at that point. 

[Nickfromwales]

1 hour ago, ProDave said:

Just out of interest how do you change these. 

In a Uniq the immersion has been made captive, so if that goes you’re completely Donald Ducked. 

[Novice]

Thanks for the replies.

Ended up getting them from Sunamp, they said they are a proprietary component. Cost £46 + VAT and postage.

I am not looking forward to doing this job but hate cold showers even more. If anyone has done this before any tips/tricks will be gratefully received.

 

[Novice]

Thanks Dreadnaught but unbelievably I managed to find my manual.

[Nickfromwales]

41 minutes ago, Novice said:

Thanks for the replies.

Ended up getting them from Sunamp, they said they are a proprietary component. Cost £46 + VAT and postage.

I am not looking forward to doing this job but hate cold showers even more. If anyone has done this before any tips/tricks will be gratefully received.

 

Why didn't SA recommend you a service / repair agent?

[Novice]

The engineer I spoke to on the phone said no service agent available that supported SA PV. The only option was to pay for him to come from Scotland to do the job.

[ProDave]

2 hours ago, Nickfromwales said:

In a Uniq the immersion has been made captive, so if that goes you’re completely Donald Ducked. 

That statement and the rest of this thread would not encourage me to buy an unservicable unit like this.

[Novice]

I believe the Uniq product could not suffer from this particular problem and there are service agents for the Uniq product. I guess the SA PV are deemed to be a legacy product 

[Nickfromwales]

9 hours ago, Novice said:

I believe the Uniq product could not suffer from this particular problem and there are service agents for the Uniq product. I guess the SA PV are deemed to be a legacy product 

A failed immersion in an Uniq was ( still is ? ) a ‘return to base’ repair which requires complete de-plumbing and extraction.

To facilitate that repair requires the purchaser to palletise, and make available the spent unit for collection. Then reverse the process when it is eventually returned.

To replace those immersions requires evacuation of the PCM and heat exchanger to get to the base of the cell. To do that, the PCM cell needs to be broken apart where it was once welded together prior to filling with PCM, evacuating the PCM and removal of the heat exchangers / thermistor string etc. A very involved process which is a non 3rd party option at ‘home’. 
The SAPV’s are serviceable at least, as I’ve done many repairs on them to date. 

10 hours ago, Novice said:

The engineer I spoke to on the phone said no service agent available that supported SA PV. The only option was to pay for him to come from Scotland to do the job.

Charming! ?

 

14 hours ago, Dudda said:

If you find it can you also post where you found it, any reference code, how you replaced it yourself etc. Any info that you think could help. I've a SunAmp about the same age and I'd have nobody anywhere here either that would know anything about them so will also probably have to do it myself if this fails also.

If you post a pic of your unit with the lid off I can use my own way back machine to advise you on the job. Iirc I set up a couple of flexible hoses to flush all the crap out of the pipework and heat exchangers but a memory refresh would help if you can facilitate the above?

[Novice]

Thanks Nickfromwales.

 

Photo with lid off

 

[Novice]

A quick update.

Just finished attending to the Sunamp PVs and I now have hot water!

I can only speak as I find and Sunamp have delivered with fantastic customer service,  admittedly they could not recommend a local service engineer, but talked me through the process including FaceTime. Far too often support from companies are promised and often fall short, not Sunamp. Maybe I was lucky.

Thank you to all here and I hope I have saved Nickfromwales writing lengthy instructions.

 

Edited November 17, 2021 by Novice

[TerryE]

@Nickfromwales I have just had one of my 2 PV units fail. 

 

In my case the heater is still measuring 17.8Ω which is what I'd expect for a 2.8kW heater.   The obvious failure is that the thermal cutout on the heater has tripped, as I read zero continuity over it.  What I am not sure about is why the heater overheated, but I need to reset it to diagnose why, and isolate the root cause.  This is the next step.  (All potable water goes through a Harvey Water Softener so we have almost no scaling in our pipework.)

 

Overall, I like these PV modules, and because I can isolate either if it fails, and I still have HW even if one fails.  They have two major design flaws:

1. The control board is a crap design: there is no decent isolation of the 240V power circuits and their track dimensions are far too small.  The main power relays are also too small.  How got this CE certification amazes me.  There is no customer / support engineer diagnostics facility.  BTW, the same board is used on their Uniq product range.
2. The gubbins as shown in @Novice pic above is squeezed into a tiny volume with no thought about access for maintainability.   The package looks nice, but so what?

I can now buy cheap ESP32 based boards with the necessary PWM output, and other I/Os, relays, etc. so my fallback alternative to replacement will be to do a complete refurb and possible replace the control with a stock alternative.  

[MikeSharp01]

14 minutes ago, TerryE said:

 I have just had one of my 2 PV units fail. 

Very frustrating. We want to go Sunamp but I still worry about reliability. We will only have one so no redundancy - two seems like overkill and we would need to stack them and getting a block that heavy up on top of its sibbling is a problem. 

[TerryE]

@MikeSharp01 that's why I like 2 off units.  The PV units are quite compact (D x W x U): 530 x 300 x 740 mm so two side-by-side are a small footprint and one does use a day's HW so long as we don't want a big bath.   They weigh 80 kg, so you really need a hoist and trolley to be one-man manoeuvrable.  The Uniq series have a bigger footprint  (W x D): 365 x 575 with height depending on capacity, so if we did decide to replace the PVs, I'd probably go for the 210e model (which is 870mm high), but I am loathed to replace the PVs after only 6 years use.

 

And it the circuit board that is the Achilles' heel, and I really can't see what the issue is with redoing it. 

Edited November 11, 2023 by TerryE

[MikeSharp01]

22 minutes ago, TerryE said:

And it the circuit board that is the Achilles' heel, and I really can't see what the issue is with redoing it.

Is the control algorithm not IP protected as you would need that to reliably control the phase changes along the flow pipe. 

[TerryE]

Nah, it's more a Q of physics, and the algo isn't that too dissimilar to how I heat my slab, but in the context my " issue is with redoing it" comment, I was really talking about SunAmp doing it.

 

Edited November 11, 2023 by TerryE