I have today  flushed out my central heating system with Fernox restorer 
ready to add Inibitor,whilst bleeding out the air I noticed that some of the 
radiator valves are in the flow and some are in the return.Is this normal ? 
or should they all be in the flow pipeline.

In an earlier contribution to this discussion,
Gordon   wrote:


> I have today  flushed out my central heating system with Fernox
> restorer ready to add Inibitor,whilst bleeding out the air I noticed
> that some of the radiator valves are in the flow and some are in the
> return.Is this normal ? or should they all be in the flow pipeline.



Both! Every radiator should have *two* valves - one on the flow side and one
on the return side. One should either be a TRV, or an adjustable manual
valve with a knob to turn. The other should be a lockshield valve  - similar
to a manually adjustable valve, but with a cover instead of a knob. This
type can only be adjusted with a spanner - which is necessary to do when
balancing the system.

It doesn't really matter which valve is on the flow and which on the
return - except that *some* TRVs are designed for the flow to go in a
particular direction - and so have to be on the appropriate side.
-- 
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

On Sun, 4 Sep 2005 22:30:10 +0100, "Gordon" 
wrote:


>I have today  flushed out my central heating system with Fernox restorer 
>ready to add Inibitor,whilst bleeding out the air I noticed that some of the 
>radiator valves are in the flow and some are in the return.Is this normal ? 
>or should they all be in the flow pipeline. 
>



It doesn't really matter too much, Anna, with one exception.    Some
TRVs are unidirectional - meaning they must be fitted to allow the
flow to go a specific way.   Sometimes they are mechanically
reversible, in which case they can go at which end you like as long as
the flow direction through the valve is correct.   There is normally
an arrow indicating flow direction.

Nowadays, though, most valves are bidirectional and it doesn't matter
what you do.   These usually have an arrow with two heads stamped on
the valve body.

If the orientation is wrong on a unidirectional valve, a typical
symptom is a vibrating or rattling noise from the valve, especially
when nearly closed.



-- 

..andy

To email, substitute .nospam with .gl

> I noticed that some of the radiator valves are in the flow and some are
> in the return.Is this normal ? or should they all be in the flow pipeline.


Most modern TRVs can be in either flow or return. Indeed, there is a good
reason to favour the return, as the water temperature can be up to 10
degrees lower, providing less parasitic effect on the TRV's room temperature
sensor.

Christian.