Radiator Query

[oldgarden]

Probably stupid question, but do all radiaotrs have to connected in a loop / circuit. Or can you for example have one seperate from rest with pipes just going diret to it from boiler?

Likewise out of curiosity does there always have to be a return to the boiler. What would happen if you just had pipe going to one radiator and ending there.

 

[ianmcd]

Two stupid questions of course all rads must be connected to the circuit

 

[muggles]

If you just had one pipe going to the radiator and nothing coming back, the radiator wouldn't get hot

 

[boringoldcodger]

can you for example have one seperate from rest with pipes just going diret to it from boiler?

There's no absolute reason why the pipes from/to the boiler can't be tee'd off close to the boiler so that one radiator is, effectively, on its own circuit. However you might find that that radiator gets more than its fair share of hot water. As the others have said the radiator has to be on a circuit otherwise no water will flow.

 

[45yearsagasman]

And you will most likely get reversed circulation.

 

[ScottishGasMan]

Assuming its a combi boiler then yes you can tee in a flow and return at the boiler for an additional rad, its not really separate from the existing rad circuit it just becomes the first radiator in the loop (again also assuming its not a one pipe system where the rads would be plumbed in series rather than the normal parallel arrangement used these days)
If the boiler is not a combi, then you have to be sure the rad is piped with the flow pipe after the pump, otherwise your flow and return pipes to the radiator are essentially both piped into the return and will get little to no circulation around it.

If you pipe a single pipe to a radiator then there is no path for water to follow, it will flow into the radiator on the initial fill and then just sit there as why would it do anything else?

 

[oldgarden]

ok thanks. As an aside, if a central heating system has a few different circuits e.g. because of different floors, do you need more than one thermostat or is it all still work on having one thermostat for all the rads.

 

[ScottishGasMan]

It depends. Technically if you only have one thermostat and timer, then there is only one circuit, regardless of the number of floors.
Multiple circuits, as in separately controllable heating zones are plumbed in slightly differently so they have individual controls that would allow them to be run seperately.

There's no issue just having the one thermostat, when heat loss and radiator calculations are done to specify what is required for a house, then the assumption is always that all the rooms will be heated by theyre radiators at the same time.