Need some advice about getting central heating sorted out?

justaquestion

Hi,

Need to get my oil central sorted out as one or two of the rads are not particularly hot, have all being bled.
The whole system would need to be rebalanced as well as a few dodgy valves replaces on rads.

The boiler part (cast iron I believe) is probably here since house was built (though not condensing) the service man did a test a few years ago and said it was over 90% efficient, so if it is that good though old, don't want to rush to replace it. The burner itself is about 16 years old and seems to be working ok.

1 I take it if burner and boiler seem to be working ok no need to replace?
2 Do condensing boilers need to be serviced as frequently as the old kind such as mine?
3 will it be possible for the plumber to replace valves on a few of the rads without having to drain the system?
4 One of the rads is warm only at top, has no air in it, I take it that is a build up of crude in rad and replacing with a new rad is probably best?

So many questions so really appreciate anyone who is able to push a little advice in my direction.
Thank you.

forgotmyname

If you suspect a rads blocked and not just trapped air why would you not want to drain it down?

If there is enough crud to cause a blockage then the whole system is likely to have some crud.

Oil filled rads? A good flush maybe all thats needed. If its the cost then drain through an oil filter and reuse it?

Mr.Generous

The system will need to be drained and flushed to make it work better, while is drained valves can be changed. Anything less is a half hearted attempt.