Ideal icos he24 boiler constant 'c' with banging noises

[Nat2000]

Following the steps now. Will keep you updated. Thank you

 

[terryplumb]

Looks like you have 3 motorised valves ,do you have zonal heating or underfloor heating ?

 

[Nat2000]

It turned out to be this one which is live coming from the hot water motorised valve! Problematic motorised valve attached below.

 

[Nat2000]

Looks like you have 3 motorised valves ,do you have zonal heating or underfloor heating ?

Yes, one for downstairs, one for upstairs and one for hot water.

 

[terryplumb]

Replace the actuator.

 

[Nat2000]

Replace the actuator.

That's brilliant @terryplumb. I have now put the two orange (central heating) wires back and left the one from faulty actuator out. Now the heating is working perfectly and going to stand by when demand is off. And showing '0' boiler status.
This is brilliant analysis and perfect steps. Can't thank you enough. You are a star @terryplumb.

 

[terryplumb]

I hope you have insulated the disconnected wires ?

 

[Nat2000]

I hope you have insulated the disconnected wires ?

Yes, they are in a separate temporary terminal block. Thank you so much.

 

[Harry Bloomfield]

When the room temperature is less than required, it triggers the pump, the motorised valve and the boiler to go ON. The boiler then keeps firing up and off depending on its internal thermostat. Is this right?

Stat triggers the valve, then valve, once in position, triggers pump and boiler.