Moved into this house a few months ago, its hot water is powered by a gas boiler but it also has solar panels. The solar panels are not producing enough hot water so I turned on the boiler. We still had only Luke warm water so I was playing around and turn a valve to closed. The valve joins the output of the boiler and the output of the hot water tank connected to the solar panels. I'm a little concerned that this will back up the hot water tank or cause us some issues, what should I do? I really would like to use the solar panel as much as possible. Thank Tony
The heat generated by the solar thermal panels needs to go somewhere. Isolating it from the cylinder may damage the system irrevocably. Solar thermal on its own will not provide 100% of your annual HWS demand anyway. The boiler will add the rest. Both need to be set up accordingly. During the summer it is likely that it will do 100% but in the winter it needs to run with the boiler to top up the heat and to also pastuerise the system for legionella protection. I also assume you have switched of the solar thermal pumpset? This would have been sufficient. However depending on system type, evaporated tube or flat plate, the system will still be absorbing heat. With tubes you can just twist them 180° and this will stop the absorption. With flat plates its a little more complicated and best left to someone who knows what they are doing. TBH I would get a technician in to deal with it. Do not just turn valves off willy nilly. For instance if the pump set is still on the pumps will be operating against a closed head now the valves are closed and will burn out the pumps unless there is a safety cut off. Call a technician. Do not mess with it.
your hot water heating should work like this water is stored in a tall cylinder with cold in the bottom and hot out at the top in your case the cylinder is hearted by 1 of 3 ways although all 3 could be working at once 1/ a electric element in the side of the cylinder about 1/2 way up 2/ a coil of copper tube in the cylinder with 1 end going to the boiler flow and the other boiler return, water is them pumped around and heat transferred from the coil into the water in the cylinder 3/a coil of copper tube in the cylinder with 1 end going to the bottom of the solar panel and the other goes to the top, water is then heated in the panel and once hotter than the water already in the tank a pump starts circulating the water around the coil untill heat is transferred into the cylinder (just like the boiler)
