When to replace radiators?

[woodyray]

This may be a "how long is a piece of string" type question, but I'm going to ask it anyway.
Our panel radiators are over 35 years old and there has always been rust inhibitor in the system.
However, over the years the system has been emptied /refilled a number of times (extend system; replace faulty thermostatic valves, replace towel rad.; changed from back boiler to combi-boiler in 2009 (Fernox then changed to Sentinel X100).....).
Next year I will be redecorating some rooms and I wonder if I should be considering replacing all 7 radiators at the same time.
There are no signs of leakage at present, but I would rather take preventative action than face problems later.
As this will be a large expense, I would value the opinions of others before going ahead.
Should I replace 35+ year old rads. or are they likely to have many more years life in them?
Comments appreciated. Thank you in advance.

 

[ianmcd]

Personally I would replace them but completely up to you, just be aware that as your rads are so old exact size replacements might not be available so best to do before decorating if you are going to do it and change all the valves at the same time

 

[flameport]

If you get new ones, make sure they are a suitable size (as in heat output) for the room - don't assume that the existing ones are correct.