Boiler Short Cycling

[arthurbear]

Hi

I have a Heatline c24 boiler ( please dont laugh ) I have been trying to balance the radiators so I get even heat to all..Its not going too bad but still have some way to go...The boiler when it gets to heat will cool down to the 60 on the display,fired up then heat to 80 ( takes about 13 seconds) turns off then goes down to 60 and starts over again and again and agian etc.The boiler had a cleaning fluid put through it sometime ago but plummer never came back to flush it..I took off my two downstairs radiators the other day and hosed them through ( lots of black water ).Also the return pipe is just warmish..The pump appears to be runnning fine..Guessing from what i've read is a blockage somewhere.Should I remove all the rest of the rads and flush them or should I connect a hose to the pipe near the front and open the valve to flush that way..Or both??Thanks for any advice.. just too add, the hot water is fine.Thanks

 

[Agile]

Do anything you can to get rid of black stuff.

The boiler probably needs setting to the correct heat output.

Unfortunately I cannot remember which of the settings it is but the manual might help you ( assuming there is one ). Its an engineers setting and not one that I would advise most DIYers to fiddle with unless they are familiar with electronics.

In any case the setting depends on which model it is and you have not specified that.

Tony

 

[arthurbear]

Thanks Agile...I want to drain the system, I have a drain tap on the dining room radiator near the front door..If i run a hose from that to the drain and open will that help..As its a combi boiler guessing it will need to be turn off/electric supply...Then when all water has stopped do I just use the filling loop to refill and will i need to bleed all radiators??Thanks again