How do I?????

[littlelegs]

Got the plasterer coming in the morning so I've just gone to take the rad off the wall. It has a valve each side but I cant turn them off - the middle slot screw just keeps going round and round....

I have the following setup

Baxi Solo 2 50PF boiler
ACL Lifestyle LP722 Programmer
Honeywell T6360/4360 thermostat
Honeywell V4073A Motorised mid position valve
Grundfos domestic circulator

Simple question - can I just drain down the CH and leave the HW intact by manipulating the Honeywell V4073A Motorised mid position valve or do I have to drain down the lot?

The rad is on the lowest floor level ....

cheers!

 

[littlelegs]

Also the water seeping out of the valves is black !!!!

 

[Hugh Jaleak]

If you cant isolate the one rad then you'll have to drain the entire system. HW and CH will common on the return so it'll all come back out that way even if the valve held watertight! Turn boiler off (and i'd isolate power!) before draining or else you may be doing more than just plastering!

Usually have a square shank under the cap on the rad valve. Screw you describe may just secure the cap? The black is oxide sludge and will stain like permanent ink. Do NOT get it on the floor or wall covering unless you are planning on replacing them!

 

[littlelegs]

thanks for the advice - will have to wait until the morning to drain then.

Do I need to replace the olives when I put the rad back or replace the section of pipe and olive??



Too late with the sludge water although but it doesn't seem to have stained


:O(

 

[superman123]

At the same time you might consider employing an engineer to cemicaly clean the system, look up the gas safe web site. there you will get a list of your closest engineers. bit late in the day though. it will take the plastera half a day to prepaire so you might have time.

 

[Hugh Jaleak]

Still should be able to undo the unions either side of the rad as you would if you had turned the valves off. Olives should remain in situ on the pipe (depending on type of valves), so wont need changing. Support valves using another wrench when attempting to loosen (and retighten afterwards) or you may well damage the pipework.

If system is badly fouled then a clean may be wise. If a chemical clean will suffice, Sentinel X400 is one chemical that can be added to help clean out, follow instructions carefully! Seriously fouled systems may require a powerflush. Either way once clean add a suitable inhibitor (Sentinel X100 or Fernox) to neutralise the water. The black stuff is oxide sludge, basically the system is corroding from inside out!

 

[littlelegs]

turned off the flow and set the heat control to 0 at the Rads and just lifted them off the pipework - all ok and no leaks.

The corrosion is odd as we only had all new Rads fitted about two years ago and the Plumber asked if we wanted an inhibitor added and we said yep.

Any suggestions as to what causes the "sludge" ? (obviously corrosion)

Is there a "quality" isolation valve - Pegler and Conex are names I have seen - or should I just scrap them and join up the Rad valves to the pipework without the isolating valves?

 

[superman123]

an inhibitor is a neutralisar . not a sludge remover. once you have cleaded the system with a quality product such as fernox or sentanel.x800 then you can add an inhibitor.

 

[Hugh Jaleak]

The 'sludge' is a product of electrolytic corrosion, basically the mixture of metals in the system (steel rads, copper pipe, brass valves etc) react with the water and corrode. The inhibitor neutralises the water to prevent the corrosion occurring.

I would fit new isolation valves if you've drained it down, Pegler should be better quality but any valve may leak of its not been shifted for years! If you need to remove the rad to decorate in future the hopefully you should be able to shut it off!

 

[Agile]

Is yourt system open vented?

And has been pumping over?

Tony

 

[littlelegs]

Hugh,
system not drained down yet as I want to bond/prime the new plaster and then paint before I put the rads back. I think I will do away with the isolation valves seeing as I can disconnect the rads via the flow and thermostat.

Tony,
its open vented (and the liquid in the feed and expansion tank is yuk)
By "pumping over" do you mean filling up?


I assume that when I drain the system the chemical clean will go in the feed and expansion tank or can I just add it the header tank before I connect the rads and let it work its way through?