Radiator: which knob to turn?

Jabba_flabba

Hello,

I want to turn off a radiator but I'm not sure which is the balancing valve and which is the on/off valve.



The left side has some encrusted sediment around the nuts so I'm thinking it's that one on the basis the previous owner of my house would have known which one and the on/off side is more likely to leak through use. I could be wrong though, hence this post.

Thanks.

patman99

Feel the pipework when the heating is on. The hotter pipe is the incoming flow and the thermostat attached to this will be the one that controls the temperature.

The other 'thermostat' should be a balancing valve that cannot (read: 'should not') be adjusted using the knb, but instead, is adjusted by popping the knob off and turning it with an adjustable spanner.
This balancing valve is what balances the heat of the radiators, so should not be randomly turned as you will find your radiator (or the ones further along the flow) no longer heats up to the correct temperature.

If you ever need to shut this valve off, make sure to count the number of turns it takes to shut the valve off and make a note of it as it will make rebalancing the radiator easier.

EssexExile

Just turn the right hand one clockwise as far as possible.

Alter_ego

Patman is right.

Jabba_flabba

Thank you, patman99. I tried feeling the temperature of the pipes as the heating comes on, after reading that method on another forum. However, both pipes seem to become hot equally and at the same rate, hence I'm unsure which knob to turn.

Biggles

Jabba_flabba wrote: »

Thank you, patman99. I tried feeling the temperature of the pipes as the heating comes on, after reading that method on another forum. However, both pipes seem to become hot equally and at the same rate, hence I'm unsure which knob to turn.

If they will both turn, turn them both down (ie clockwise). You will probably find that only one will.

patman99

Just thinking that the instal might be a DIY job with the installer using standard rad thermostats at both ends for some unexplicable reason.

Anyway, all the rads I have dealt with so far, have the actual temperature thermostat on the left hand side.

Another method is to feel the pipes as the heating first switches on.
The return pipe should still be colder than the inflow pipe as the hot water won't have had a chance to fully circulate around the system.

patman99

Re: biggles post.

Make sure that you count the number of turns it takes to turn each valve off just in case they have fitted 2 thermostats instead of 1 thermostat and 1 balancing valve.

If one valve simply spins without locking-off, then that's the balancing valve. This is the one that should you need to turn-off, you need to remove the top to access the valve and not the number of turns needed to turn it off.

Jabba_flabba

In the end turning the left hand knob clockwise turned it off. Thanks to everyone that replied.
:beer: