Today's conundrum.

[Marvin]

My Towel radiators are definitely full of water.

They are quite hot up to about half way up.

 

Why?

 

 

[nod]

Airlock 

[JohnMo]

Bleed them

[Marvin]

17 minutes ago, nod said:

Airlock 

Nope. Full of water  bottom half fully functional as a radiator.

[Marvin]

6 minutes ago, JohnMo said:

Bleed them

Nope radiator completely bled.

[Marvin]

34 minutes ago, Marvin said:

My Towel radiators are definitely full of water.

They are quite hot up to about half way up.

 

Why?

 

 

 

[nod]

Turn the other radiators off and let some water out of the towel rail 

Then bleed it 

[Marvin]

5 minutes ago, nod said:

Turn the other radiators off and let some water out of the towel rail 

Then bleed it 

Hi @nod. I can quite catogorically say there is no issue with either water circulation or air in the radiiator.

 

I confirm the towel rail rad is full of water from the top to the bottom. The hot water enters the rad on one side and exits on the other but only heats up about half way. 

 

I know you think it's a air issue but it is not.

[Marvin]

One of the aformentioned.

and yes I am supposed to be decorating the room for Christmas ?

Edited December 3, 2021 by Marvin

[joe90]

I think it may be an airlock elsewhere, I think that’s what @nod means, if you shut the others off and bleed water from that rad for a while if there is an airlock in the pipework it may force it through.

[ToughButterCup]

@Marvin, when you bleed the radiator, does that process result in an immediate increase in temperature at the top of the radiator? And if so, is there a subsequent reduction in temperature at the top of the rad? If thats happening, it might well be that the rad is being supplied by air from downstream in the system

[nod]

25 minutes ago, joe90 said:

I think it may be an airlock elsewhere, I think that’s what @nod means, if you shut the others off and bleed water from that rad for a while if there is an airlock in the pipework it may force it through.

Thanks Joe 

 

I get this all the time with our rentals 

Not sure why 
Everything off Boils pressure up 

Dish under one of the valves Let some water out Open the bleed screw at the top 

and wait for that bad boy to heat up almost instantly 

Re pressurize your boiler when your finished 

[Marvin]

45 minutes ago, joe90 said:

I think it may be an airlock elsewhere, I think that’s what @nod means, if you shut the others off and bleed water from that rad for a while if there is an airlock in the pipework it may force it through.

Hi @joe90. Thanks but I understood exactly what @nod was saying and usually he would be right. Having been corgi registered in my time I would know all about air locks....

 

There is no air lock.

[Marvin]

42 minutes ago, ToughButterCup said:

@Marvin, when you bleed the radiator, does that process result in an immediate increase in temperature at the top of the radiator? And if so, is there a subsequent reduction in temperature at the top of the rad? If thats happening, it might well be that the rad is being supplied by air from downstream in the system

Hi @ToughButterCup

No.

And I confirm that there is no air in the top of the radiator.

 

[Marvin]

26 minutes ago, nod said:

Thanks Joe 

 

I get this all the time with our rentals 

Not sure why 
Everything off Boils pressure up 

Dish under one of the valves Let some water out Open the bleed screw at the top 

and wait for that bad boy to heat up almost instantly 

Re pressurize your boiler when your finished 

The radiator has been running for 12 hours in its present condition.

It is the first time in my life I have seen this happen. 

 

I can only guess the reason and no one has come up with (possibly) the right answer yet.

 

You have to think of something completely different. I am waiting for someone who has had this happen to respond so no-one thinks I'm mad.

Edited December 3, 2021 by Marvin

[dpmiller]

any chance the top bars are fake, with no flow through?

 

also, have you bled *both* sides at the top?

Edited December 3, 2021 by dpmiller

[Marvin]

I believe that the solution is to lock off both sides of the radiator, drain the contents from the bottom and pour it back in the top. If I am right surely someone with a heat pump has had to do this before.

 

 

8 minutes ago, dpmiller said:

any chance the top bars are fake, with no flow through?

Hi @dpmiller

 

But you would think it was a possibility.. .

No. It worked perfectly fine for 2 years. Both of the towel rails.

 

Edited December 3, 2021 by Marvin

[Marvin]

This is the other one:

 

 

If no one else has had this problem then I must be wrong? Yes it full to the top. Yes the lower half is running freely and hot.

Edited December 3, 2021 by Marvin

[PeterW]

This happens with towel rails. They don’t circulate properly as the flow goes the shortest route. 

[markc]

Close the outlet side to almost shut, I've just had  similar problem with a couple of rads, bled perfectly but water takes the easiest path and with outlet too wide open the hot water seems to just flow across the bottom

[markc]

Damn, Peter bet me to it again

[Marvin]

7 minutes ago, PeterW said:

This happens with towel rails. They don’t circulate properly as the flow goes the shortest route. 

You are far closer to the truth than you know.

 

I fixed the small one:

 

 

Time to catch the water.... notice the colour.... :

 

and the results:

 

Wait! What's this?:

 

 

The water in the top of the radiator was clear, but the water running below is rich with antifreeze...

[Marvin]

So @nod was correct with the action required: Bleed the rad (Well remove water from radiator). But not quite the reason IMHO.

 

@PeterW was correct about the lack of circulation but not the reason. IMHO (the towel rails ALWAYS circulated to the top in the last 2 years). 

 

And @dpmiller had the most way out thought which I think makes @dpmiller a great solutionist!

 

But my conclusion are:

 

1. The towel rails don't circulate as well as the radiators.

 

2. The antifreeze effects this problem even worse (did I mention I added it yesterday?) 

 

3. I was too mean to want to drain loads out the radiator thereby diluting the antifreeze mix when refilling, so my plan of isolating the tower rails, emptying into a bucket, and refilling worked.