Hi all,

I added a radiator to my sister's central heating system and fitted a
bigger radiator in her utility room. I drained the system before
doing the work then tried filling and bleeding afterwards. Bleeding
was a bit of a drama as air was trapped and I eventually ended up
letting the pump run for a little bit to get things moving.

Now the problem....

I have "successfully" bled all the rads - i.e. opening the vent valve
produces water (rather than air or nothing in the beginning!) however
am having a mixture of results with the rads...
- the upstairs ones in the front of the house are fine
- the upstairs ones in the rear of the house are very slow to heat up
- the downstairs ones are all fed from above with pipes running down
the walls in each room. These heat very slowly and not to the temp of
the upper one. Almost as if these are heat by heat transfer in the
water/ pipes rather than hot water flowing through them.
- the utility room rad (looks like it is the last one on the circuit
but not sure!) doesn't come on at all....

My theories and what I have tried...
1. there was an air lock - I have independantly attached the flow and
the return of the utility room rad to the mains water and filled the
system up from there. Still no impact on the rad.
2. Something wrong with the rad - I have connected the flow and
return for the utilitty room rad together (bypassing the rad) still no
change
3. I have let water run out of both the flow and return of the utility
room until the water was hot (ie came from a "working" part of the
system) Still nothing.
4. New valves are dodgy - disconnected each from the rad and turned
on. Water flowing fine.

I am now at a loss of things to try.... All my money was on the air
lock and connecting to the mains working... no such luck.

Does anyone else have any cunning plans????

thanks in advance for all your help

Lee.