Manual rad valve: always on full blast

[mike004]

The majority of my rads have TRVs. One rad has a manual wheelhead valve (Pegler terrier).

This rad is always full on, even if I turn the wheelhead valve almost completely clockwise.

Is the valve was a TRV, I would suspect that the valve was faulty. But can manual valves go wrong like this?

 

[buck51]

If you turn your kitchen tap "nearly off", is it on or off????
Its on!!!

 

[mike004]

If you turn your kitchen tap "nearly off", is it on or off????
Its on!!!

Yes. But it's not on full blast.
I though manual valves were able to control flow to the rad. Not just being on or off.

 

[buck51]

Your missing the point, if you turn it off the radiator will cool down, if you turn it on the radiator will get hot, Its doing its job,

 

[Whitespirit66]

Turn the valve fully off. If the rad stays cold, it's OK.

 

[mike004]

Turn the valve fully off. If the rad stays cold, it's OK.

Because all my other rads have TRVs, I have to leave the manual valve open. I think this is a building reg.

So, it looks like this particular rad (the biggest one in the house, in the living room) is always going to be on full blast.

 

[steve32]

[quote
So, it looks like this particular rad (the biggest one in the house, in the living room) is always going to be on full blast.[/quote]

Yes

 

[Whitespirit66]

Turn the valve fully off. If the rad stays cold, it's OK.

Because all my other rads have TRVs, I have to leave the manual valve open. I think this is a building reg.

So, it looks like this particular rad (the biggest one in the house, in the living room) is always going to be on full blast.

That's as it should be, if the room stat is in the living room too. If the stat isn't in living room, or you don't have one, then you need one in there. As the living room is the room that needs to be warmest, and where you spend a lot of time, use the stat to control room temp in here. Not the rad valves.

 

[Charnwood]

What do you mean by "full blast"?
If you mean it gets really hot, no matter how much the WH valve restricts the flow of water into the rad it will always be hot water, so the rad will always get hot "if I turn the wheelhead valve almost completely clockwise".

Manual rad valves do nothing to control temperature. On or off, i.e. hot or cold they're your choices.
In fact, that is also the case with TRVs. All they do is turn on or off. The temterature of the water is determined by your boiler.

Room stat, as suggested.

 

[vulcancontinental]

A manual valve is either on or off. Do you test the temperature of the radiator by touching the top of it? If so that is the part that will always be hot as hot water will rise.

You restrict the flow of water into the radiator not the temperature so less of the overall surface of the radiator will be as hot if you reduce the floe rate through it.

Remember nearly all the effect of the valve will be in the first rotation from off even though the head may rotate five or six times completely. Turn the valve off then open up a quarter of a turn to see whether the room is warm enough; if not open another quarter etc till you reach a comfortable temperature in the room then stop. Wait an hour when the cold weather arrives between adjustments.

 

[bengasman]

I though manual valves were able to control flow to the rad. Not just being on or off.

You are wrong.

 

[dal5band]

If all the other valves are off (TRVs) then all the pressure is going through this one radiatore - so you only need it to be on a quarter of a turn to get enough flow to fully heat it. The manual valve will control the flow but only for the first quarter of a turn - after that, it's all the radiator needs. So effectively it's on or off !
You could try turning down the valve at the other end. But the flow is quite complex as it depends on what the other radiators are taking.

 

[mike004]

Turn the valve fully off. If the rad stays cold, it's OK.

Because all my other rads have TRVs, I have to leave the manual valve open. I think this is a building reg.

So, it looks like this particular rad (the biggest one in the house, in the living room) is always going to be on full blast.

That's as it should be, if the room stat is in the living room too. If the stat isn't in living room, or you don't have one, then you need one in there. As the living room is the room that needs to be warmest, and where you spend a lot of time, use the stat to control room temp in here. Not the rad valves.

I don't have a room stat anywhere.
So in the living room I have the manual rad on at full blast. There is also a smaller TRV rad which doesn't get so warm (because the output from the big manual rad is determining when it switches on and off).

Not very energy efficient at the moment!

 

[vulcancontinental]

Then do as I explained earlier.

Next cold weather turn the big rad off then open the valve a quarter of one rotation.

Ignore the temperature at the top of the radiator, your body is the best sensor you have not your hand at the hottest section.

After an hour if you're warm enough that's it, if not open the valve a quarter turn more. repeat as necessary.

Get a room stat. I disagree with some posters here who say put it in the warmest or most often occupied room but frankly the way you describe the system it would seem to be best in your case. Get a wireless one then you can move it from room to room until you find the best position for you; you live there we don't.

 

[mike004]

Then do as I explained earlier.
Next cold weather turn the big rad off then open the valve a quarter of one rotation.
Ignore the temperature at the top of the radiator, your body is the best sensor you have not your hand at the hottest section.
After an hour if you're warm enough that's it, if not open the valve a quarter turn more. repeat as necessary.

My understanding is that the manual valve is either on or off.
But your instructions suggest that changing the setting of the manual valve will affect the rad temp.