Central heating circuit won't circulate after replacing radiator

[branchlake]

Hi - I'm a new poster and have just stumbled upon this very useful forum. I would be very grateful for any advice.

I have a Eurocombi Ariston boiler that's about 10 years old. It operates without a thermostat on a simple on/off control within the boiler itself. There are five radiators throughout my house that are all on a single water circuit.

I noticed last winter that the radiator in the front room was not circulating much water through it (although the other radiators worked just fine...) so on the advice of my handyman I replaced the radiator in the front room the other day by myself. I'd never done this before but it looked very straightforward from videos and instruction I'd seen online and from in-person advice I'd got from the plumbing shop.

I closed off the control valve flow and the outlet valve flow, emptied the water from the radiator, undid the two valve nuts (one on either side), replaced the radiator, re-attached the valve nuts, opened the control valve flow and filled the radiator by cleeding out the air, and then opened the outlet valve flow. This should have opened the circuit back up, in theory.

After doing this, I switched on the heating at the boiler. It fired up immediately. I could feel the hot water feeding out through the pipe underneath the boiler, but no hot water was reaching any of the radiators anywhere in the house. This leads me to believe that the circuit is not circulating somehow. I don't know how this can be, however, as it is entirely open. I didn't want to leave the heating at the boiler level on too long, as I didn't want to damage the circulation pump.

I don't know what more I can do, and I cannot think of a reason why the circuit wouldn't be working anymore. Does anyone have any ideas/suggestions?

Any and all advice is very welcome and appreciated.

Many thanks

 

[Gray0689]

Air lock or pump knackered

Try turning all rads off at hand wheels/ trvs
And open one at a time if heat comes turn off and go to next one

 

[PlumbBobBob]

have you repressurised the boiler if it is a combi?

 

[kris]

Bleed radiator , then repressurise to 1 bar if required , make sure lock shield is open ,

 

[stevetheplumber]

probably the trv that was stopping the old rad working is still stuck shut ,never listen to handymen when it comes to plumbing

 

[Eric withy]

You probably got air lock or pump not circulation like it should valves turn of sticky trv or no pressure in system

 

[joni os]

Bleed pump by loosening large central screw. Ensure auto vents are working. Don't get water on PCB or other electrics.

 

[ShaunCorbs]

Bleed pump by loosening large central screw. Ensure auto vents are working. Don't get water on PCB or other electrics.

he cant do that as hes not gas safe