Air in system.

[Riley]

Afternoon guys

I have a bit of a head scratcher

I look after several properties for a Company that deals with the rehabilitation of alcoholic and drug addicted adults. I suppose you could call them halfway houses.

Each of these large properties have very well installed heating and hot water systems. One of the systems is causing me issues. Every 4 to 6 weeks The staff at the house have to bleed the radiators as the ones at the top have almost no water in. There are no leaks and no reports of any frequent pressure drops essentially everything is working perfectly apart from the top floor radiators losing heat after 4-6 weeks. The house is a three story townhouse in Southampton. This one has a sealed system with a Worcester 37 CD I Installed. Worcester not my boiler choice but still better than lots. The system was properly power flushed at the install and the Magna clean is virtually spotless so I do not believe that it is the radiators degrading.

I just wondered if anybody else had any thoughts or pointers that I might try

 

[Best]

Are you sure there are no pressure drops? People tend to give wrong info.
Pressure drop will mean air in highest rads.
Some diyer could be messing about with an air key on some of the rads, thinking they can bleed them often, or maybe some other pressure drop elsewhere.

 

[Riley]

No pressure drops because I know the guy who holds the keys to the cupboard with the filling loop he said he never has to touch it

 

[Simon F]

have you tried a flame on the radiator when bleeding to see if its or or hydrogen?

 

[Best]

I know you said it's a well installed system, but just wondered is there any plastic non barrier pipe? Never seen that myself, but just wonder could it be a problem.
Or perhaps an auto vent fitted somewhere where it will suck air into system while circulating pump is on, such as a return pipe?
I saw this on a job where a plumber fitted auto vents on the end of a rad circuit on the final drops to rads. The return was sucking air down into some rads & pipes.

 

[IDCHAPPY]

Must be air ingress or a leak somewhere dude, we have a hotel with a similar issue but presume it's the huge mish mash of copper everywhere.
I presume a leak in my case or corrosion.

 

[Riley]

have you tried a flame on the radiator when bleeding to see if its or or hydrogen?

Sadly not as they'd bled it before I was there

 

[Riley]

If it were a constant air ingress would we not expect dirtier central heating water? If it weren't for the pungent inhibitor smell you could've drunk this.