concord wrs boiler changing radiator

[rickospark]

Hi,
I am changing a radiator on my heating system, which appears to be of the sealed type ( there is no header tank )
I have done this job on open vented systems previously, but I'm not sure how to drain and refill this type.
I cannot see a filling point/tap anywhere on the system - would this be inside the boiler casing ? it's an old Ideal Standard Concord WRS 55 boiler.
Any help would be appreciated,
Many thanks.....

 

[45yearsagasman]

A WRS on a sealed system? Are you sure? All I can tell you is that the boiler does not incorporate a fill loop. Is it fully pumped or gravity HW and pumped heating? Is the cylinder a primatic?

 

[rickospark]

Hi Pete,
thanks for your reply.
The answer to your questions..
no I'm not 100% sure,
The storage cylinder is in the loft ( its a bungalow ) with the cold water tank above.
looks like pumped heating and gravity HW.
The cylinder may be a primatic- I've looked at some images and it looks close, is there a way to identify it properly ?
thanks again..

Mark.

 

[Armo74]

A primatic cylinder will not have a seperate feed and expansion tank which means you would only have 1 header tank (CWSC), If you are swapping rad like for like just close both valves undo union nut and drain that rad. Also if it is primatic inhibitor cannot be added.

 

[rickospark]

Many thanks,
it does look like a primatic cylinder..
the downside is the new rad is a lot smaller than the original so I will have to alter the pipework,
any advice on draining/refilling would be much appreciated !

 

[Hugh Jaleak]

A Primatic (single feed indirect cylinder) may have a label on the cylinder stating its a Primatic, will also be missing the cold feed and vent pipe as well as the smaller F&E cistern. Filling and venting takes place inside the cylinder.

To drain: Turn off supply to cylinder, (if that doesnt stop then you'll have no option but to drain cold storage cistern as well, or tie ballvalve up if preferred). Attach hose to suitable drain off, (other end outside to drain), open drain valve and let system empty. Open bleed screws in rads to assist with emptying. Once empty, close bleed screws and drain valve.

Fit new rad. Turn water supply to cylinder back on. Allow to fill, bleed rads and pump. Switch system back on. (It may be noisy as trapped air shifts around, may need to bleed rads again after a while when noise settles as air may collect in the rads.)

Alternatively, freeze both pipes you wish to alter, fit new rad.

 

[rickospark]

many thanks for your advice Hugh,
that's my job for the weekend sorted then...

Mark

 

[rickospark]

Hi all,
I just wanted to thank everyone for their replies.
The radiator change went smoothly with no hitches.
I followed the advice to refill the tank slowly with a hot tap running, the heating and hot water came back soon after as normal.
thanks again!
cheers,
Mark.