Solutions for a Leaking SolarTwin Panel
It is now becoming apparent that Solartwin panels have a limited lifespan. This seems to be around 25 years and there will always be exceptions that last longer.
If your panel is around that age and you are seeing a steady flow of water coming from the panel during a period of dry weather then it is likely that your panel has sprung a leak. I have recently replaced the internal pipework in an early panel and this page explains the type of task involved.
Task 1: Get the panel on the ground. These are not light weight and scaffolding is probably unavoidable. The Yellow wired Controller Sensor is located in the rear insulation sheet and must be freed before moving the panel to the ground.
Task 2: Remove the the screws securing the frame at two corners to release one side of the frame.
Task 3: Slide the 'clear' polycarbonate sheet out to reveal the Heat Collector assembly.
This is going to need a paint touch up with a car aerosol spray before refitting
Task 4: Remove the assembly and lay flat on a surface. This comprises two sheet of aluminium riveted together sandwiching a serpentine layout or 24 metres of soft 16mm OD, 12mm ID silicone pipe. The metal sheets are held together by 230 pop rivets, each of which are easily drilled out with a 4mm drill bit.
Old brittle pipework ................................................Back sheet............................................................New pipe taped in position for reassembly
Task 5: Separate the sheets to reveal the silicone pipe. Replace this with new tubing, I used 12mm OD, 8mm ID pipe instead and it worked well, held in place with strips of gaffer tape to aid reassembly.
Task 6: Place the two sheets back together. Replace the rivets to secure the metal sheets and allow them to gently contact the tubing inside the aluminium panels. Touch up the black paint as necessary.
Task 7: Clean or replace the Polycarbonate sheet. New sheets are around £100 so you may choose to keep the old sheet and clean with a mild abrasive and bleach with a peroxide solution (hair dye!) . If you choose the latter approach then very fine wet and dry sandpaper works well on heavily tarnished panels, after which the sheet can be refitted with the cleaned side inwards.
Task8: Replace the sensor but move it to allow it to stay in contact with the silicone pipe as it exits the panel (ie the upper pipe once installed) .
Task 8: On my own panel the back of the KingSpan type insulation board was badly degraded so I glued cheap tin foil onto it using PVA glue which seems to have worked OK and seals the weather out.