DimplexSolar Solcu-12 issue

MICKEYG

Hi all, we have had the above system for water heating for the past 10 years and it has been great. It was last serviced just before COVID.

About mid Sept it just stopped heating the water. The panel temperature is showing high temps (even today it got up to 90C) but the water never heats. I know that you get less as we head into winter but in prior years on the sunny days we had in the past month we would get a good boost.

The gas boiler is heating the water fine. I checked the manual and could not see anything in the troubleshooting section.

Any idea?

Also, any recommendations for a service should that be the solution.

Thanks in advance for your help

dathi

https://www.manualslib.com/manual/764377/Dimplex-Solcu.html

page 59 onwards deals with fault finding ,sounds like ether you have air in system or pump seized

MICKEYG

Many thanks. Probably well beyond my skill to fix. I contacted one servicer but there is a 12 month waiting list. Is that common?

John.G

Have a look around and you will see a pump with a (red) expansion vessel nearby, there will also be a pressure gauge, if this is reading 1.0 bar or greater then you may have a pump problem, if reading 0 bar the system will need top up with solar fluid but youshuld check the air end pressure of the expansion vessel with a (car style) pressure gauge, if this is reading 0 bar then pump it up to 1.5 to 2.0 bar, if already reading anything greater than 0.5 bar then fluid top up required.

MICKEYG

This is what I see. The red piece at the end twists and seem to let air/water in/out.

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John.G

That looks like your heating system to me, have a look on the end of the red piece which is a relief valve and if there is 3 bar stamped on it then it is to do with your heating system. Your solar system will have a pump and a red expansion valve + a pressure relief valve with 6 bar stamped on it, see what the pressure gauge which should be close by is reading.

MICKEYG

https://www.boards.ie/discussion/comment/119798231#Comment_119798231

I can't find a second pressure gauge. It may be hidden behind the tank.

This is most likely past my skill level now so i will need to get someone in to take a look.

Thanks for all your help. Very much appreciated.

Edit. Found it up in the attic. Will check it out later when I get a torch.

MICKEYG

So pictures attached. Pressure looks to be at zero and tank (with pipe coming out of it) seems empty - I assume this is where the solar fluid goes. Should this have a seal on it?

I looked at the red expansion vessel but there does not seem to be an obvious place to put a car style pressure gauge.

Again, many thanks in advance for the advice and help.

IMG_20221027_185851.jpg

IMG_20221027_185904.jpg

IMG_20221027_185911.jpg

John.G

The valve is right underneath the expansion vessel, it will/should have a plastic Disc sized dust cover that you can either unscrew or prise off, the valve is then exposed, its very unlikely but worth checking for pressure here, if very little or none pump it up (if not already at pressure), if fluid level OK the water side pressure gauge should start rising as well, stop pumping at 1.5/2bar, if pressure gauge doesn't start rising then you will have to get somebody in to recharge/change the solar fluid.

dathi

the can in picture number 1 is to catch any discharge from the pressure relief valve

as already said valve is located on the bottom of red cylinder in pic 2

and in picture number 3 at the very bottom of picture there is a brass piece with a Perspex window this is a flow gauge that shows how much solar fluid is flowing when the pump is on . attached to the right of this is two round threaded nuts the size of a washing machine hose outlet this is where new solar fluid is added