Flow & return valve positions

[pyounger]

Since embarking on my journey to replace a radiator I have been taking a more in-depth look at my system and notice that some radiators have the lockshield on the flow whilst others have them on the return. Surely this can't be right and must affect the ability to correctly balance the system especially as most have TRVs.

Should I swap over the incorrectly fitted rads?

 

[Dan Robinson]

Depends what trvs you have.

 

[kevplumb]

if you restrict it going in or out it dont make any odds

if as dan suggests odd / old trvs they might chatter

 

[pyounger]

Th TRVs are quite new Drayton TR4s. I also notice that the bleed valves are oddly mixed - some on the side of the TRV others on the side of the lockshield

 

[kevplumb]

so it makes no odds

 

[Dan Robinson]

Well either you had different fitters (right or lefthanded) or like me he was trying to place them on the least intrusive side of the Rad.

 

[pyounger]

Ok thanks. And the same goes for the bleed valve - doesn't matter which side that's on (as long as it's on the top!).

 

[RonO]

Surely if the lockshield is on the flow it messes up balancing? I was told to balance you open up bothe valves then adjust the lockshield on the return so it is approx 12c lower than the flow.

If the lockshield is on the flow you'd have to have that wide open and use the TRV to shut off - which you couldn't do

 

[Dan Robinson]

Think you need to be told things by someone who knows what they are talking about Ron

Some radiators have baffles in them that DOES affect the direction of flow. However, most rads are universal.

 

[RonO]

Maybe, but that is how it is described in many books and on-line tutorials.

 

[D_Hailsham]

Surely if the lockshield is on the flow it messes up balancing? I was told to balance you open up both valves then adjust the lockshield on the return so it is approx 12c lower than the flow.

If the lockshield is on the flow you'd have to have that wide open and use the TRV to shut off - which you couldn't do

All a lockshield valve does is control the flow rate though the rad. The slower the flow rate, the greater the temperature drop across the rad. It does not matter which end the LS valve is placed, the effect is the same.

Read How to balance a CH system

 

[Dan Robinson]

Maybe, but that is how it is described in many books and on-line tutorials.

And most of those are based on incorrect, out of date and often both, information.

I have several books written for the industry that I gave up reading due to the woeful inaccuracies and terrible writing/spelling errors.

 

[RonO]

Fair enough Dan thanks