Some time after a radiator TRV is switched to cold, it begins to whine. This
is very loud. When I turn the radiator on, a bubbling noise is heard and the
radiator stops whining. Radiator is bled, and there is quite a lot of air -
probably from the bubbles. Radiator is again switched to cold when not
required. Cycle repeats. What gives?

I'm a bit worried about draining all the pressure from my CH system if I
have to bleed the radiators a lot.

Bill wrote:
Some time after a radiator TRV is switched to cold, it begins to whine. This
is very loud. When I turn the radiator on, a bubbling noise is heard and the
radiator stops whining. Radiator is bled, and there is quite a lot of air -
probably from the bubbles. Radiator is again switched to cold when not
required. Cycle repeats. What gives?

I'm a bit worried about draining all the pressure from my CH system if I
have to bleed the radiators a lot.


keep bleeding and repressurising. These things are not rare.

On 14/12/2010 15:29, Bill wrote:
Some time after a radiator TRV is switched to cold, it begins to whine. This
is very loud. When I turn the radiator on, a bubbling noise is heard and the
radiator stops whining. Radiator is bled, and there is quite a lot of air -
probably from the bubbles. Radiator is again switched to cold when not
required. Cycle repeats. What gives?

I'm a bit worried about draining all the pressure from my CH system if I
have to bleed the radiators a lot.


Is this a new problem, or has it always done it? What make/model is the
TRV - and do you know whether it's bi-direction?

Some TRVs have to be installed in a way which ensures that water flows
through them in the correct direction - otherwise they are noisy. Could
yours be one of these - installed the wrong way round?
--
Cheers,
Roger
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"Roger Mills" wrote in message
...
On 14/12/2010 15:29, Bill wrote:
Some time after a radiator TRV is switched to cold, it begins to whine.
This
is very loud. When I turn the radiator on, a bubbling noise is heard and
the
radiator stops whining. Radiator is bled, and there is quite a lot of
air -
probably from the bubbles. Radiator is again switched to cold when not
required. Cycle repeats. What gives?

I'm a bit worried about draining all the pressure from my CH system if I
have to bleed the radiators a lot.


Is this a new problem, or has it always done it? What make/model is the
TRV - and do you know whether it's bi-direction?

Some TRVs have to be installed in a way which ensures that water flows
through them in the correct direction - otherwise they are noisy. Could
yours be one of these - installed the wrong way round?

I don't know - we had a new boiler put in last Christmas and all the
radiators were left in place but got new TRVs. Most of the year the upstairs
radiators in a lot of the rooms are switched off because the house gets
heated sufficiently during the warmer summer months. I don't recall the TRV
misbehaving last year - I thought it was just the fact that they had been
off for a long period of time that had caused the buildup of air.

"Bill" wrote in message
...

"Roger Mills" wrote in message
...
On 14/12/2010 15:29, Bill wrote:
Some time after a radiator TRV is switched to cold, it begins to whine.
This
is very loud. When I turn the radiator on, a bubbling noise is heard and
the
radiator stops whining. Radiator is bled, and there is quite a lot of
air -
probably from the bubbles. Radiator is again switched to cold when not
required. Cycle repeats. What gives?

I'm a bit worried about draining all the pressure from my CH system if I
have to bleed the radiators a lot.


Is this a new problem, or has it always done it? What make/model is the
TRV - and do you know whether it's bi-direction?

Some TRVs have to be installed in a way which ensures that water flows
through them in the correct direction - otherwise they are noisy. Could
yours be one of these - installed the wrong way round?

I don't know - we had a new boiler put in last Christmas and all the
radiators were left in place but got new TRVs. Most of the year the
upstairs radiators in a lot of the rooms are switched off because the
house gets heated sufficiently during the warmer summer months. I don't
recall the TRV misbehaving last year - I thought it was just the fact that
they had been off for a long period of time that had caused the buildup of
air.



Could be due to it being off for a while - could be that the new system is
circulating water faster than before. Is TRV on Flow or return (flow gets
hot first) - compare with others