Radiators - help

[kevplumb]

if the rads are sucking air in it means the feed water isnt getting in tothe system
hence we need to figure out how the system fills

 

[Plump Bob]

Oh, I see! Right, I'm off home at lunch time to have a prod at the pump and I'll try to find the name of the tank and see if I can identify the feed tank.

I'll get back to you with my progress this afternoon.

Thanks a lot, by the way

 

[kevplumb]

if it has a lid on the top open it and have a look in the other tank is inside

 

[Plump Bob]

That's it. It's something like that but looks older and dirtier. I found a label that said it was a:

Type 4 Combination Hot Water Storage Unit

I had a look in the top (using a mirror and a torch - there wasn't much space). There was water in the top bit, when I pressed the ball thingy down, water does come through.

The lid wasn't actually on though. Should this always be on?

I also checked the pump. It seem to be spinning when I started the heating. But, after 10 minutes, none of the pipes leading to or from it were getting warm, although the pump itself was getting warm and none of the radiators were getting at all warm either.

Any ideas?

 

[kevplumb]

there is a feed tank inside (not the one with the ballvalve in it)
ist usually round app 6"" dia this is what feeds the heating
you have a blockage either on the pipe in (if its empty )
or in the pipe out (if its full )
try www.elsonhotwater.co.uk

if you click on saphire it shows a cutaway veiw

the bit you want is in the middle above the red coil products / all products / indirect / saphire

 

[Plump Bob]

So, is there anything I can do to unblock/tell which is blocked? Or is this a job for the pros?

 

[kevplumb]

could try getting a drain snake down the pipes you might be lucky
otherwise get somebody in

 

[Plump Bob]

Hi,

I managed to get heat to a couple of the radiators last night! Having read up as much as I could about how central heating works I poked around my system a bit more.

Basically, on the side of the tank I found a sticker that says:
"This unit fills the boiler and radiators automatically from the ballvalve through the primary feed and expansion tank."

Then, using a mirror and a torch, I looked in to the tank with the ballvalve and saw, at the bottom, two pipes sticking up. The water level covered one, but the other was sticking out. I also noticed that there seemed to be a mark on the side of the tank where the water (maybe) used to come up to.

So, I figured that, until I took my radiators off to decorate, there had always been enough water in the system. And, over time, maybe the ballvalve level dropped, so less water was being held in the system? So, when I put the radiators back on, there wasn't any new water being able to get into the system to fill it up...

I held the ballvalve down to fill the tank some more, until the pipe that was sticking out was covered and then started the heating. Result! I managed to get heat to the first 2 radiators on the circuit (with the rest turned off).

So, now I reckon I have to gradually fill the rest. Any pointers about the best way to do it?

Also, do you think what I've described above sounds OK?

Thanks

 

[kevplumb]

if you go to www.elsonhotwater.co.uk
proff centre/tech data/amber

it showsa decent cutaway drawing of your tank
ignore thu pumps etc the tank is the same

how much water was in the feed tank ?
how high was the pipe sticking up?
what dia is it ?

 

[Plump Bob]

In the cistern the water level didn't seem really high. It covered one of the pipes, that I guess feeds the main tank, but the other one was sticking out.

This one, I reckon is 22mm, although it looks to be of smaller dia on the cut away drawing you pointed me to. Also, it is in the same kind of place as the drawing - at the same end as the ball.

I'm pretty sure that these were the only two pipes leading out of the cistern.

What do you reckon?

 

[kevplumb]

the pipe on the drawing is the feed to the heating but its shown as flush
never come across one sticking up / how far ?
mind you all ive done with elsons is remove them and descale them
if you raise the water level in the tank to cover this pipe how far below the overflow will the level be ?

 

[Plump Bob]

The water level only needs to be a couple of cm higher than is currently set with the ballvalve.

Both feeds stick out. The main tank say 2 cm and the heating feed about 4 cm.

The tank doesn't actually say Elson anywhere on it, as far as I can see. It looks pretty much the same, but not quite. Could explain the sticking up pipes.

 

[kevplumb]

good point give it a go
if you get stuck shout
let us know how you get on

 

[Plump Bob]

Arrgh! Thanks v. much for you guidance I'll let you know the outcome

 

[Plump Bob]

Ooh, one more question:

If you've got a circuit of, say, 3 radiators. The first 2 are open and the last one is closed. In the pipes that supply the radiators, does the hot water flow as far as the last radiator or does it just go as far as it needs?