Spoke to the dealer this morning. He was going to talk to his partner and Elddis about the situation. His answer was that Elddis are willing to put corner cap repairs on under warranty. We had discussed his taking the van back and my swapping it for another van - he had a Coachman that is the same layout, but his offer involves a large payment on my part to 'part exchange' that I find unacceptable in that he values the coachman at top book and my van at trade in - in effect he would be making money on both vans at my expense.
My view is that corner repairs make it obvious that the van has a fault and devalues it - it would be unmerchantable I believe is the term Prof used.
Question is what is the next step. Shall seek legal advice I think.. The list of repair work to the van in the 4 years since new is long but the short timespan since the rear panel was changed -9 months is my main complaint.
I understand your disappointment with the caravan, and if it had been mine I'm sure I would also be pursuing the best outcome, but sadly the situation is not quite as clear cut as you hope.
You still have not told us how old the caravan is, only that you have owned it for about 4 years. That could men you purchased it second hand 4 years ago. But assuming you purchased it new, by my reckoning it must have been new prior to Oct 2015, which is significant as the Sale Of Goods Act was in force, rather than the 2015 CRA, and this affects how the matter may be handled.
It must be remembered that both the SoGA and the CRA only apply to contract you have with the seller. The manufacturers warranty is a totally separate contract between you and the manufacturer.
The later CRA takes many of its characteristics from the older SoGA. , but in at least one relevant respect it differs. Where as the later CRA sets out the case that the seller can only make one attempt to repair before the customer has the right to request a full refund, the earlier set out no specific limit on the number of repairs.
It's also unclear if the repair undertaken through the manufacturer's warranty scheme would count as a sellers repair, though it certainly supports the case for the original product being defective.
In the strictest sense, even with the history of failures, the caravan as a whole has remained fit for purpose, In so far that none of the faults has rendered it 100% unusable, it has towed and provide accommodation, including sleeping, heating, cooking and hygiene.
In particular your reference to "merchantable quality" which in the light of the additional history you have provided may need some more detailed clarification.
It is my view that if a new caravan is sold and within weeks of normal ownership the end panel cracks, that would suggest the end panel is not of merchantable quality. It clearly had a fault either of design, material or workmanship.
The manufacturer recognised this under its warranty scheme and replaced it, But it seems it has again failed in a similar way, so the replacement end cap or workmanship of teh repair was also not of a merchantable quality.
The problem seems to be well known, and the manufacture has undertaken a repair program on other affected units where the repair consists of additional caps presumably to strengthen the affected parts. The available evidence so far suggest that this repair method is working, and thus would most likely work in your case also. Presuming the success of this repair method is sustained then it would be judged as an effective remedy or merchantable quality.
Its a question of timing, As a new caravan it demonstrated a failure of the panel due to an inherent fault. But despite this failure the caravan is still functioning after 4 years. SoGA only remains active in England and Wales for 6 years after the point of purchase, and as this period expires the scale of remedies diminish towards zero, however the time scale clock pauses whilst a a reported fault is investigated and resolved, so here again the validity of your claim may have different outcomes.
As time goes by the onus falls more heavily on the customer to be able to prove the faults are indicative of faulty design, materials or workmanship.
SoGA and the CRA were never designed to be a customer charter to take advantage of a seller, it was to make retail sales as fair to all parties. So its important to be scrupulously honest in these matters.
As you may see from my comment the matter is far from clear, so I strongly advise you consider very carefully what action you are prepared to take, and I suspect it may be wise to seek professional advice.