Guys, I am trying to get to the bottom of why my underfloor heating isnt quite working correctly. Firstly, I have two manifolds. The Bottom manifold is where the hot water comes into the system. The water then flows to the output valves. These are open or closed. Currently all open. The Top manifold is the return. Each "Zone" has an adjustment valve, which can be opened up or closed, depending upon how many turns, will allow more or less water to return through the system. First question. Is this right? Shouldn't the adjustable valve be on the bottom? Secondly, I "think" I have heard that the water from the boiler should be set to 65 degrees. Now, is this the water temperature on the side of the cylinder in the airing cupboard (Photo below). Or do I set this physically on the boiler? (Photo below) Thirdly, I have heard about balancing the system. My understanding of this is that each zone has a different length of pipe. If the pipe length is short, then you need to send less hot water there, as the return water will be back into the system quicker. I have also read somewhere about if the boiler turns off and on when its trying to send hot water to the UFH. Apparently if I turn off all of the UFH (Close all valves) and let it cool down, then open just one zone, the boiler should fire up and service that zone until it reaches the desired temperature. I "think" my boiler turns off and on regularly, rather than staying on. I am going to try this out later today to confirm. My question is, if the boiler is turning off/on rapidly, what could be the cause? Faulty pump, balancing, faulty valve, something else? Can anyone guide me please. Doobs.