Do all radiators require valves?

[yj6aa]

I have a gas combi boiler and I have noticed that one, whilst decorating of the radiators in out CH system does not have a themostat valve on it? All of the others have them.

Am I right in thinking that the valve gets to temp and then cuts the water supply off, the boiler then detects the pressure change and then stops heating the water.

The radiator is the furthest out on the system, at the back of the house in the bathroom.

Will this affect the way in which the system heats up, as It never seems to get to tempreture.

Any thoughts or ideas will be appreciated

 

[Bahco]

That will be your bypass rad which is a safety measure your installer has put in to protect the boiler.
Leave alone
If your rads do not get up to temp, try balancing or bleeding.
Do a search on this forum if you are unsure