A local heating system is presented. The local heating system comprising: a first heat source (10) connectable to a heating grid (110) and arranged to extract heat from the heating grid (110); a second heat source (20) connectable to an electrical energy grid (120) and to transform electricity feed through the electrical energy grid (120) into heat; a heat emitting device (30); a distribution system (40) for circulating heat transfer fluid between the heat emitting device (30) and the first and second heat sources (10, 20); and a controller (50) configured to control the first and second heat source's (10, 20) relative outtake of heat from the heating grid (110) and the electrical energy grid (120), respectively.

A district energy network interconnecting a plurality of thermal loads and for redistributing thermal energy therebetween, the network comprising: a primary circuit loop for working fluid, at least two thermal loads thermally connected to the primary circuit loop, at least one of the thermal loads being capable of taking heat from the primary circuit loop and at least one of the thermal loads being capable of rejecting heat into the primary circuit loop, an energy centre connected to the loop and capable of acting as a heat source or a heat sink, and a control system adapted to provide to the primary circuit loop a positive or negative thermal input from the energy centre as a balancing thermal input to compensate for net thermal energy lost to or gained from the at least two thermal loads by the primary circuit loop.

A flushing bypass system, particularly for use in a district or communal heating system, has a primary circuit 2 capable of supplying heat to a secondary circuit 10, the secondary circuit normally supplying heating through radiators 11 and/or hot water from tank 14 for occupants. The primary circuit has a furcated strainer 3 upstream from at least one heat exchanger and a limb of the furcated strainer is connected to a heat exchanger bypass assembly. The bypass assembly comprises a valve 21, which may be a timer valve, a manual valve or a smart valve, having an input 20 connected to the furcated strainer and an output 24 connected back into the primary circuit downstream of the heat exchanger. When the valve 21 is closed fluid passes through the furcated strainer to the heat exchanger and when the valve is open, fluid bypasses the heat exchanger and flushes contaminants from the furcated strainer back to the primary circuit downstream of the heat exchanger.

A local heating system is presented. The local heating system comprising: a first heat source (10) connectable to a heating grid (110) and arranged to extract heat from the heating grid (110); a second heat source (20) connectable to an electrical energy grid (120) and to transform electricity feed through the electrical energy grid (120) into heat; a heat emitting device (30); a distribution system (40) for circulating heat transfer fluid between the heat emitting device (30) and the first and second heat sources (10, 20); and a controller (50) configured to control the first and second heat source's (10, 20) relative outtake of heat from the heating grid (110) and the electrical energy grid (120), respectively.