Draining a sealed system and adding a rad?

Thanks again hi spec will now have to wait till they come back.
Rob

Rob
June 2007

>no header tank then how would this system be topped up?

when you can have a look at the copper cylinder if it has a label on the side saying primatic it only has one header tank instead of two that is for your water supply for the copper cylinder and heating. it is seperated by a air bubble in the copper cylinder. the air bubble is easerly lost when draining system, the art of keeping the bubble when refilling is to fill the system slow.
they are an horrible system fitted when central heating first got going in the early 70s, very few about now.
and to stop it filling while draining just surport the ballvalve in header tank. (tie it up so it don't drop)

to get a better understanding type primatic systems in to google.

>Does the header tank have to be directly above the boiler?

no can be anywhere, as long as it's higher than the


>straight joint without a stop so it slides along the pipe

don't use plastic pushfit. brass compression joints that have the olives will be ok
or if your soldering yes you can get a straight coupler that slides they are called slip couplers. they don't have the indent in the middle to stop it sliding.

where are you located ?
don't try b&q, go to plumbcentre or any descent plumber's merchant. they help you better with the slip couplers.

hi-spec plumbing
June 2007

Hi spec one more from a pain in the a***e

We decided to have ago but using compression joints.
They've gone away for two weeks so don't know name of boiler or if name on h/w storage tank.

Can't see I noticed last visit a football type can in the airing cupboard with pressure gauge, then I wasn't looking for one then.
Don't know name of boiler but if not as you describe and their is no header tank then how would this system be topped up? and would one have to turn the in coming mains off to drain.?
Does the header tank have to be directly above the boiler?
as this may be in an upstairs cupboard. This may depend on loft layout it may not be possible to site it in the loft to be direct over boiler and may be in a bedroom cupboard. Now I'm not sure he's looked properly.


re: the fitting of the Tee is their a 'sliding joint' ie: a straight joint without a stop so it slides along the pipe so we can fit the Tee with a copper section in the Tee and slide the straight back on to it?. this was mentioned to me yrs ago and never saw one so was he pulling my leg then? Of course if compression joints [underfloor] can't be used then it will have to be a fitter.

Rob
June 2007

Thanks Hi-spec may have to get plumber as I we can't do solder fits, I've tried without much success on bench so daren't try live.

rob
June 2007

>I know we can close all rad valves and just drain the pipes but I fear that some of the valves might not shut the water in the rads off

why would you want to shut all the rad valves, and unbalance the whole system and get more problems.
just drain the system and leave the other rad alone.


>Are push fit joints suitable for central heating?

not really use coper and solder pushfit can and do blow off and once under floor are noy easy accessable.


>What’s the knack in getting the Tee joints in the flow pipes if they don't move enough?


hard to exsplain but comes with experience.

>As the addition is upstairs do we need to drain the whole system?

no as long as the water is below where you are working


as for the sealed system.
have you a red metal shape football in the airing cupboard in the pipework with a gauge onit reading bar ?

if not its not sealed system.

also check you copper cylinder in cupboard does it say direct or primatic on a label on the side ?

hi-spec plumbing
June 2007