Losing pressure in Central Heating system - going crazy!

hollie.weimeraner

I've used these successfully in the past (on plastic pipes as well) https://fernox.com/product-category/leak-sealers/

cheme7676

ThisIsWeird said:

cheme7676 said:

i think that sounds pretty solid to me. Now it’s just about deciding what smell to use. You quite rightly said something distinct but I also want it to be something pleasant because if it’s a leak in someone’s bedroom, they aint gonna be happy with that constant smell!

And monitor the pressure carefully as you reopen the isolating valve.

There are lots of these wee bottles of concentrated smelly oils - peppermint, lemongrass, lavender, pine, orange, eucalyptus... Which one would be the most noticeable to you - the least like current ambient smells?

I was thinking something along the lines of a distinct poundland cheap bottle of eau de toilette. The theory in my head is that the volatility of it will make the smell very apparent as it’s more volatile than water so will readily escape. Essential oil could work but I’m not sure how miscible it is in water and the volatility it would give and intensity of smell etc.

cheme7676

hollie.weimeraner said:

I've used these successfully in the past (on plastic pipes as well) https://fernox.com/product-category/leak-sealers/

I’ve tried Sentinel leak sealant but unfortunately wasn’t a good solution for me. Slowed it down for 2 weeks then back to the drawing board

cheme7676

Just put some perfume in and waiting. Been around 20 mins but no smell out of condensate or anything yet.

i noticed the condensate trap was pretty dirty and very misty again (like a dark grey) even though a week ago it was cleaned. Not sure if that indicates anything…

Will wait in the meantime

ThisIsWeird

Exciting! Well, it is for us watching from this side...

cheme7676

Also I forgot to mention. I noticed my bathroom radiator valve had some green deposits on it, but I couldn’t be sure if it’s the stuff plumbers use or if it’s a leak. When I checked online, it only affects copper, which my valves shouldn’t be? And the pipes which supply the valves are plastic. Also in the past when I had tissue on the valves over a few days it didn’t show a sign of water. So not sure about that.

in the meantime I wait

ThisIsWeird

The green is verdigris, and will likely be from the brass valve (under the chrome).
It's common for tiny leaks like this to produce such deposits. 
Your leak is surely sizeable, tho', so I suspect that ain't it. :-(
You can clean it off with WD40 or similar, and a toothbrush or wire brush (but don't wire brush a plastic pipe...)

FreeBear

cheme7676 said: Also I forgot to mention. I noticed my bathroom radiator valve had some green deposits on it, but I couldn’t be sure if it’s the stuff plumbers use or if it’s a leak. When I checked online, it only affects copper, which my valves shouldn’t be?

Valve bodies are usually a brass (or bronze) which contains a fair proportion of copper. So yes, you can get a green deposit (verdigris) forming. Give it a wipe with a cloth soaked in Bicarbonate of Soda to neutralise any acid.

cheme7676

Thanks both. I isolated that radiator completely now.

flue and condensate still don’t show hint of perfume smell, also tried DHW and don’t think there is any leak into that, can’t smell anything.

I sat down with my head in my hands, at the bottom of the staircase and no smoking gun. Then I heard the sound of (what I imagine to be) a drop of water behind a radiator…

I searched everywhere around it, couldn’t find a single drop of water. Then I heard it again. I realised it might be behind the wall. Whilst CH was on, I timed each drop, whilst CH was on it dropped around once every 45s over a 5 min period. I then turned off the CH and waited 15 mins, testing it now and getting around 1 drop every 10 seconds. My guess is as it cools down, any escaping water will evaporate less (total stab in the dark here), until it gets cold enough that the leak closes.

The radiator is on the bottom floor and I can’t see any signs of water damage on the wall or skirting. Flooring is tiles and it’s an outside wall. Very small sprinkle of rain outside

Dont know if it’s just radiator and metalwork expanding/contracting. Whether it’s a genuine leak or whether it has anything to do with water ingress from slight rain outside

km1500

not sure if this is a stupid question or not but on the basis any idea might help... - have you tried a turning the central heating pump on but with the boiler not firing. 

(I can do this on my system by turning the thermostat up but the boiler water temperature off)

ie is it an increase in water pressure through the radiators because of the pump that is causing a possible leak or is it a temperature thing that's causing a leak