Trv valve failed

[AndyPRK]

Turned rads off except 2 towel rails and the the bypass valve.

Rad didn’t get hot.

I am worrying a little about the system now.
I’ll check the system pressure in the morning when it’s cold

Maybe get a plumber after Xmas.

The trv shouldn’t have failed as it’s always on max. And I have noticed a gradual cooling in the hall, until Sunday when it was obvious the rad was stone cold.

 

[terryplumb]

You need to turn all rads off .

 

[AndyPRK]

Having said that, I think the pin was stuck in when I first touched it

I wd40 It several days ago

 

[AndyPRK]

Humm. Pressure already looking a bit low now cooled.

I think I must have let a bit of pressure out a few weeks ago as it was approaching the red.

I’ve been happy with the pressure when the system is hot. (End of green scale)

But now I look when it’s cold it’s below 1bar which i know isn’t enough from experience.

 

[JohnD]

Did you lose interest in the idea of turning ALL the other radiators off?

You are now describing a problem with the pressure vessel, which is different.

 

[AndyPRK]

From my expectance, if the pressure is too low this can cause some remote rads not to heat. Sadly in this case doesn’t appear to be the issue but was worth ruling out.

I'm away for Xmas.

 

[JohnD]

From my expectance, if the pressure is too low this can cause some remote rads not to heat.

Wrong.

 

[AndyPRK]

So I closed off the towel rails.
Closed off every rad except the troublesome one.

Minor improvement. I'm just getting a bit of warmth now at the input to the rad, but the rad isn't warming up

Any advise on what to do next gratefully received

 

[terryplumb]

Remove the rad ,take outside and flush through . Whilst rads off the wall ,see if a strong flow of water comes out of each valve when opened.

 

[AndyPRK]

ok thanks.

I drained down the system about 18 months ago, and I was surprised how clean the system was. No black or grey water. You could see though the water.
It's not dirty now

 

[terryplumb]

If that hall radiator will not heat ,with every other radiator turned off ,then one or both valves are not free flowing ,the radiator is blocked ,or the pipework is blocked or severely restricted.

 

[AndyPRK]

Well on the day of the last post, I turned on the upstairs towel rails one turn.

For the first time in ages I got some warmth in the troublesome rad, but not enough to get excited about.

However today I have proper heat! See how long it lasts !

 

[AndyPRK]

Note to self.

I had a nice warm winter.

Today I took the rad off.
And flushed it. Water wasn’t coming thru.
The normal valve wasn’t very open.
Opened it and the rad is running free.

The TRV valve is ok allowing water thru.
And blocks water when the pin pressed

Tried to get the fitting out the rad with a 16mm spanner but its not having it.

 

[AndyPRK]

Note to self.

With the heating being off a day or so, the problem has returned.
Opened rad valve at least one turn, a small improvement but still have the issue

 

[AndyPRK]

Note to self

Removed the bypass valve today.
Loads of black crud had built up in the pipe to it.

Drained the problem radiator. A little bit of dirt came out, but not loads.

Will need to drain/clean/flush the system if problem still present