UlsterRugby1999 Posted April 1, 2012 Share Posted April 1, 2012 Good morning kind people. Long time no post. I trust you are all well.I have just finished installing my own solar water heating system. I have a 300lt tank, 36 Evac tubes, controller, pump, expansion tank etc. There are 3 probes - top tank, bottom tank and collector. The controller is set to factory settings (10C degree diff between for switch on and 5C degree diff for switch off). The flow from the collector is connected into the correct end of the manifold and that is the end where the collector probe is connected also. The problem is that over the last few days since installing the system, the flow pipe, from the collector, isnt really hot at all as it enters the tank. Our water isnt being heated anywhere near the 60C degree mark and we are having to force heat with the electrical element. As I write this the pipe is very cool and its full glorious sunshine outside. The tops of the tubes which enter the manifold are hot enough that they would burn you if you tried to hold onto them.Any ideas anyone? Please. Cheers. Paul. Link to comment Share on other sites More sharing options...
Théière Posted April 1, 2012 Share Posted April 1, 2012 Are you getting good water flow? the cool water suggests it not getting to the collector properly. Link to comment Share on other sites More sharing options...
UlsterRugby1999 Posted April 1, 2012 Author Share Posted April 1, 2012 MerciThéière - as far as I know we purged the system of air after we filled it withthe water/anti-freeze mix. We followed the instructions. I have just had my sonclimb up there and put a digital thermometer on the flow pipe as it leaves thecollector and it showed 38°C. The T1 (bottom tank reading) reading on thecontroller shows 32°C. We have virtually clear skies and temps of approx. 16°C.Surely it should be hotter than that exiting the manifold. Link to comment Share on other sites More sharing options...
UlsterRugby1999 Posted April 1, 2012 Author Share Posted April 1, 2012 What about increasing the flow rate via the circulating pump? Link to comment Share on other sites More sharing options...
BIG MAC Posted April 1, 2012 Share Posted April 1, 2012 Check the isolators either side of the pump if you have one and is the pump circulating or needing vented Link to comment Share on other sites More sharing options...
Théière Posted April 1, 2012 Share Posted April 1, 2012 Should still be hotter than 32 though?? [8-)] Link to comment Share on other sites More sharing options...
UlsterRugby1999 Posted April 1, 2012 Author Share Posted April 1, 2012 HiBIG MAC, there is one isolator valve, after the pump, which is open. The pumpis circulating and I increased it from its No1 speed to No2 speed and the tempactually dropped a couple of degrees. By vented do you mean bled. I have bledthe pipework system containing the HTF but not the pump. We've actuallyunseated all 36 tubes and re-seated them and this actually produced a fewdegrees more (but would this have occurred anyway as we did this earlier in themorning). Given the lovely afternoon we had today I'd have thought that themanifold would have been way hotter than it was. Link to comment Share on other sites More sharing options...
UlsterRugby1999 Posted April 1, 2012 Author Share Posted April 1, 2012 Agreed Théière – but I don’t know what else to do. Its up to37°Cjust now but I’d still have thought with the clear blue skies today it wouldhave been much higher. Is there a possibility that the manifold has a problem, orcould I be seating the tubes incorrectly? I’m more inclined to look at me beforelooking at the actual parts first. Link to comment Share on other sites More sharing options...
UlsterRugby1999 Posted April 1, 2012 Author Share Posted April 1, 2012 Mmmmmm - strange things here - T1 - bottom of tank shows 36C --- T2 - Collector shows 37C --- T3 - Top of tank shows 38C. Surely if the bottom of the tank is 36C and the collector shows 38C then the pump should switch off as the differnetial is less than 10C. Or have I completely misunderstood this whole thing. :-( Link to comment Share on other sites More sharing options...
Théière Posted April 2, 2012 Share Posted April 2, 2012 Can you measure the temp at the emitter on the top of the tube before it enters the manifold? Link to comment Share on other sites More sharing options...
UlsterRugby1999 Posted April 2, 2012 Author Share Posted April 2, 2012 Mmmmmm– not sure I fully understand Théière. Do you mean the return point at thecollector?Update– we spent an age yesterday removing and shaking the tubes and inner elements,lots of other wee things to try and find the problem. THEN, I discovered thatour spark friend had actually connected the differential pump directly to itsown feed and not via the controller. I connected the pump to the controller.Obviously the pump had been running 24/7 and also during the night so that musthave been having a totally negative effect. So, today, with brilliant clearblue skies and lovely temps the T1 – lower tank temp peaked at 45°C, T2 –collector at 54°C and T3 – top tank at 49°C. That’s a vast improvement fromprevious days. Given the temperature (21°C) and clear skies today did I do okayor should I have expected more. I have no previous experience of this but in mywee head I had imagined it would have been somewhat more.Thanksto all for all your input, as always. 100% appreciated. Paul Link to comment Share on other sites More sharing options...
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