Solid fuel heating

nadiahealy

hi can anyone give me a simple explanation of how a solid fuel gravity system works, heating a few radiators(leak radiators) and an indirect cylinder for hot water

Pete67

Water expands as it heats up, therefore hot water is less dense than cold water. This characteristic can be exploited to generate circulation by good system design.

Simple example, solid fuel boiler on the ground floor, flow connection from top of boiler jacket is piped to the top of the indirect coil in a cylinder, as far as possible rising all the way, with limited horizontal runs, and no dips.

Return from bottom of coil to bottom of boiler jacket. Piping should be generously sized with swept bends where needed.

Light fire, water in boiler begins to heat up, and rises upwards as it becomes less dense than the cold water. it reaches the coil in the cylinder where it is cooled by the surrounding cold water. This cooler water is forced downwards to the boiler return by the hot water coming up the flow side where is gets heated and repeats the cycle.

See here

nadiahealy

thanks,could you have cylinder on ground level or does it need to be higher than stove for this type of system

aujopimur

To install a cyl. on the ground floor put it on a pedestal with its return higher than the boiler flow.
The flow can be piped up and over with the expansion taken off the highest point, and the return piped below.

nadiahealy

cheers,i have also come across a system where pipe stat is on flow on cylinder upstairs but not effective,the water blows up expansion before it heats flow pipe to signal pump or heat cylinder,i seen the pipework and its rising all the way to cylinder,would it be expansion pipe is to close to stove for gravity circulation to occur as it is teed off the flow just as it rises from stove and go,s across to cylinder

aujopimur

The expansion pipe should connected to the highest point on the flow.

nadiahealy

yea cheers,understanding it a bit clearer now

nadiahealy

sorry one more question if a gravity flow on a system does not work properly,could i relocate pipe stat on flow pipe at stove to operate pump,would this be ok