2 Rads working one isn’t

[Joshua Manning]

I’ve just moved in to a property I don’t have a big knowledge of plumbing at all I have a Vaillant Boiler when it’s in normal mode only 2 out of 3 radiators work but if I put it into service mode the one that doesn’t work then works help please ?

 

[ShaunCorbs]

Turn the ones that work off does the one that doesn't heat up now ?

 

[Harvest Fields]

Turn the ones that work off does the one that doesn't heat up now ?

May just need forcing through. Try the above And let us know what happens