Water aroung radiator tap

[OhGranny]

Hi
Have posted here previously regarding my new combi losing pressure.

http://www.diynot.com/forums/viewtopic.php?t=164926

I topped up the pressure last Sunday and it is low again this morning.
Checked all around the system.
I lifted the cover off the tap on the hall radiator and found water seeping out of the top where the gland nut is.
It was only a few drops but would this be enough to lose pressure in the system?
I have given all the gland nuts around a quarter turn if they were a bit loose.
This right?
Thanks
G.

 

[swidders]

If it works then it's right! Let us know how you got on.

 

[OhGranny]

Hi Swidders and all
I looked a little closer and I'm not sure now that the water was coming from the gland nut it could have been evaporation trapped under the plastic knob.
On closer inspection (after lifting up the floorboards and checking every joint I could get to) I spotted the paint on a pipe to a downstairs rad. had expanded like a sleeve around the pipe and water was weeping down inside the paint from a loose compression fitting.
I wrapped a tissue around the joint and it was quite wet after about 5 mins.
Gave it about 16th of a turn and it is dry now. Pressure looks a bit healthier overnight but not certain I could have lost so much pressure from that.
Time will tell!!
BTW noticed that CH pipes under floorboard originally had insulation on. Whoever has worked on it in the past has left it off in many areas.
Should the pipes be insulated or will they get too hot?

 

[Tipper]

Too hot is not an isue. What you are trying to do is keep the heat in and avoid losing valuable heat under the floor or even freezing if it's a bit drafty down there.

If you can slide some pipe insulation onto the pipes then do as much as you can reach. You may want to lift floorboards and check it all out when you next decorate or change carpets or similar.