sealed cemtral heating

[G1zm0]

hi
ive a sealed central heating system, and i want to drain it, the drain plug is located outside , and when i open it up and open a radiator bleed valve nothing comes out.

i have noticed a pipe that bends with a valve on it, its above the mid pos valve i want to change.

i have included a pic of this, is it anything to do with it.

View media item 36071
View media item 36072

could someone say what im doing wrong, and when i go to refil it, do i just add 2 bar to the red tank and open valve on radiator to bleed them and fill system up.

thanks for any help

 

[Agile]

I expect the washer on the drain cock is stuck.

You need to remove the screw fully and poke it until you get wet.

Refill to 1.5 Bar cold.

While its drained you could check the air pressure and set to about 0.9 Bar.

All of this and much more in in the FAQ on this site!

Tony

 

[G1zm0]

thanx for replay, but does anyone know what the screw is for on the picture with red circle on it? (top one)

its above the mid pos valve

how do i check the air pressure? i will read the faq section when i get home tmoz.


i got a honeywell 7 day timer to fit to system aswell,

when refilling system and switching water off do i just do it from the red tank?

 

[gremlin16]

thanx for replay, but does anyone know what the screw is for on the picture with red circle on it?

Looks like a manual bleed vent.

 

[G1zm0]

would i use that valve to bleed the system, aswell as radiator valves

 

[ChrisR]

Yes!

 

[bengasman]

t
i got a honeywell 7 day timer to fit to system aswell,

Make sure it is a completely independent timer that allows you to set the dhw and ch at times that do not overlap.

 

[G1zm0]

today i tryed to drain the system, i opened up the outside drain tap all the way,

then i opened the rad bleed screw and filled a larg tumbler up with the water from it then closed it,
i checked outside and no water had came out, so i poked about inside the drain plug with a allen key to c if there was anything stuck up there.

i tryed take the screw and the nut of but to no avail.

the inside valve thats circled in red on top pic, i was gonna try open that but water would go all over the electrics.

what can i do to get the water drained?

also on the expansion tank the air is at 3.5 bar, is this ok

 

[45yearsagasman]

What are you measuring that reads 3.5 bar?. With respect you have been given some good advice on how to drain a system, but as yet with no luck.
I noticed you also wanted to change the 3 port valve, (for what reason you don't say). I would seriously consider calling a pro who would be able to do that all for you in about an hour, saving a lot of heartache.

 

[Boilerman2]

Come on Guys!!! surely the valve with the red knob and a copper pipe attached is the SAFETY VALVE???

 

[45yearsagasman]

Sorry Bm2, I don't get your post. What valve,what red knob? If you mean the prv on the red exp vessel then forgive me. Using that for draining is not good practice and looking at the system layout would not do the job.

 

[petit_pablo]

Come on Guys!!! surely the valve with the red knob and a copper pipe attached is the SAFETY VALVE???

Glasses on time
The red circled part near the MPV in the top pic is a manual air bleed.

The safety valve is in the second pic and isnt circled.

 

[G1zm0]

hi, im changing the valve as its giving me hot rads when hot water only is on,
i discussed this in another thread.

the pressure dial on the expansion tank is reading 3.5 bar, when its usually 1 bar.

i would get a plumber if i could afford it, hence doing it myself, ive read the faq and no help as it wont drain.

also want to change a rad as one i got is rusty and started to leak

in short of cutting a pipe i dunno what to do .

 

[bengasman]

also want to change a rad as one i got is rusty and started to leak
in short of cutting a pipe i dunno what to do .

When one rad rots through from the inside, chances are pretty good that your whole system is severly corroded.
Starting diy on that kind of scale when you have no idea what you are doing, is likely to end in a disaster with much higher costs as a result and the initial problem still not solved. It certainly is not a matter of: nothing ventured, nothing gained.
Do yourself and your family a favour, and budget for a pro.

 

[G1zm0]

i dont know if its rusted through, i dont think it is, its at the left side of the rad, the nut that joins the pipe and rad together is where its wet, ans its prob been sitting on top of the rad and its rusted, its not holed.

and it doesnt leak when the system is off, i just want to get the hot water working and will see abt a new system next year