Unusual Noise coming from boiler after bleeding radiators

[gizmo_the_great]

Apologies if this is posted elsewhere - I had a search and read //wiki.diynot.com/plumbing but could not find the answer.

My heating system has been working fine. All the radiators hot. The other day I took one radiator off to decorate a room. Then put it back, opened up the valves, and warm water ran into it (heating was on at the time). I then bled the radiator until water began to peep out the valve. Then, after about 10 minutes, I noticed all the radiators went cool, and then I heard a noice coming from the boiler.

I have an unusual heating system. I have a cold water tank, a hot water tank, a boiler, a pump, and little red bowler-hat sized valve thingy with a pressure valve on it. Last time I had a problem with the boiler the plumber said to make sure the pressure valve sits between 500 - 1000 units.

Overall view of boiler :

Bowler-hat sized unit showing pressure valve :

Well, when I heard the noise, I looked at the valve and it read 0! So I tweaked the valve on the pipe that feeds the little bowler sized unit until the line on the valve started to climb. At around 1000 I turned it off, and there it has remained. The noise stopped. And the heating came on. But then, after a few minutes, it went off again and has not come back on since!

So, what I am hoping to learn is what is the problem likely to be so that when I ring the plumbers up I sound like I have at least some idea as to what the problem is.

Thanks a lot

Ted[/url]
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[Agile]

Running the system with no water pressure is not very good for it!

Luckily for you the boiler has a little device to protect it from you !

It will have switched itself off but you can put it back on again by looking under the front surface of the boiler for a plastic rusty coloured thingy and pushing it up to reset it.

Thats made more difficult for you because you insist on having the bottom cover hanging loose.

Tony

 

[gizmo_the_great]

Thanks very much for you help.

Do you happen to have a hyperlink to a picture of the 'plastic rusty coloured thingy' so that I know what I'm looking for? And when you say 'the front surface of the boiler', I assume you mean I need to remove the front face to gain access to it?

(The bottom tray is not like that deliberately - the bracket that held it on snapped months ago).

Cheers

Ted

 

[gizmo_the_great]

I found the reset button. It was in a hole at the bottom of the boiler. I pressed that, and the heating came back on. Brilliant, I thought. But after about 10 minutes, it turned itself off again!

I noticed that the pressure valve mentioned earlier krept up from 900 to just over 1000 at around the time it turned off. Could this be the problem? How do I go about resolving this? Does anyone know what might be causing it (I thought if the pressure was OK it should just run?).

Thanks

Ted

 

[gizmo_the_great]

Fixed it! Turned out to be two things :

1) when I initially re-filled the system (when it was cold) I put too much in taking it up to 1.0 bar. So when the boiler was on and the presuure expanded, it tipped it over the 1.0 bar limit and turned off (as you say, a protection against humans!).

2) I bled all the radiators several times, but what I did not spot was the bleed nipples on the flow and return pipes that run directly from and to the boiler. One was fine, but the other was FULL of air - it took abou two minutes to bleed it, and I did so all sorts of air bubbles made their way through the radiator pipes.

After that, I re-bled all the other radiators just to make sure, turned the boiler back on (had to press the reset switch first of course), and now it all seems to be OK. It's much quiter now too, and the pressure it steady at about 0.7 bar.

Thanks for your help. I hope my write up will help someone else.

Cheers

Ted