Radiator valves - which is which?

Shandon

How do I work out which is the on/off valve on a radiator?
Moved into a rental house and their are no plastic handles on most of the radiator valves.
How do I know which switch is the on/off valve? Both will turn in both directions when I put one of the few plastic handles on it?

MicktheMan

The pipe that heats first is the "flow" and the valve on this is the one you use to turn on/off.
The other pipe is the "return" and is used to balance the system and once setup, ought not to be touched.

Shandon

MicktheMan wrote: »

The pipe that heats first is the "flow" and the valve on this is the one you use to turn on/off.
The other pipe is the "return" and is used to balance the system and once setup, ought not to be touched.

Thanks a million mick. How do I know when the other one is set up

Shandon

Shandon wrote: »

Thanks a million mick. How do I know when the other one is set up

Should it be just turned fully anti clockwise ie fully open?

MicktheMan

If all the rads heat up equally fast and to roughly the same temperature then the system is balanced.

MicktheMan

Shandon wrote: »

Should it be just turned fully anti clockwise ie fully open?

Generally not

doolox

See articles onlone re: balancing radiators.

Basically you need to make the radiator nearest the heat source (boiler) to be almost off by using the return pipe valve to within 1/2 a turn of being off. The next rad in line can be 3/4 turn etc and the last rad is all on.

A plumber will sort this out fairly quickly and have the right gear to do it.

The balancing valve is used to stop the first rad in line from "grabbing" all the heat and the last one getting none at all.

Shandon

doolox wrote: »

See articles onlone re: balancing radiators.

Basically you need to make the radiator nearest the heat source (boiler) to be almost off by using the return pipe valve to within 1/2 a turn of being off. The next rad in line can be 3/4 turn etc and the last rad is all on.

A plumber will sort this out fairly quickly and have the right gear to do it.

The balancing valve is used to stop the first rad in line from "grabbing" all the heat and the last one getting none at all.

Thanks for that. Using micks advice I checked which pipe heated up first to try and work out which is the on/off valve.
Is this a cut and dried way of working it out as on some rads it's the left hand one while on others it's the opposite. Should they all be on the same side or does this make sense?

Shandon

Shandon wrote: »

Thanks for that. Using micks advice I checked which pipe heated up first to try and work out which is the on/off valve.
Is this a cut and dried way of working it out as on some rads it's the left hand one while on others it's the opposite. Should they all be on the same side or does this make sense?

Still confused as to which are the on/off valves as different sides are heating up first on different radiators. Is micks advice above definitely right and should I just go with the pipe that heats up first?

Tokyo

Shandon wrote: »

Still confused as to which are the on/off valves as different sides are heating up first on different radiators. Is micks advice above definitely right and should I just go with the pipe that heats up first?

Yep, the above advice is correct - the pipe that heats up first is the input - i.e. where the on/off valve sits. Most plumbers will try to keep the valves on the same side where possible, but really it just depends on how the radiators have been tee-d off the main supply and return pipes.