DIY Doctor UK DIY Forums

Hi - have what i believe to be reguler open vented sytem.

2 nights ago the pipes began making very loud banging noises and the heating cut out-looking at the boiler LED 'overheat' was lit,so I reset the boiler [ on first floor] and tried again, loud clanging noises seem to come from pipse leading to the loft space & then boiler cut out after a few seconds with the overheat LED again.

So this time went into the loft and found when the boiler is reset and turned on again the vent pipe over the F&E tank seems to be making all the noise and jets ouit steam and boiling water for few seconds until he boiler cuts out with overheat LED.

We have an immersion element in the tank which worksgiving hot water when turned on. But their is no CH or HW from the controls [ program ] as this causes the boiler / overheat and venting as above.

Im struggling to see what could be causing this

There is normally inside the boiler a thermostat on the outlet pipe which will stop this happening, it likely needs replacing, and is likely in an area not accessible without being gas safe registered, so you will need to call some one out.

Also it should have caused the reset button on the immersion heater to have also tripped, if this has not happened then also the immersion heater thermostat needs replacing.

But make sure it is resettable, as clearly you don't want a fault on central heating boiler to stop you using immersion heater. Some once activated they need replacing.

Also be aware some header tanks can not take the heat of boiling water, there was a tragic case where the water tank split and a baby was killed as a result, when solid fuel heating is used they also use a stronger water tank able to stand boiling water.