Worcester Greenstar 30Si at 0 Bar

[BenHulland]

Hello,

I have a problem with our (2 and a half year old) WB Greenstar 30Si. It was, and has been, working perfectly until yesterday morning when the hot water started running cold. The boiler is now reading 0 bar pressure and will not fire up (at least I don't think that it will, it makes the usual start up noises and then the solid blue light starts flashing).

I then checked that there weren't any leaks and that all of the radiators were full of water. No leaks and absolutely no air in the radiators (the water came out with pretty good pressure).

Then I attempted to repressurise the system with the filling loop. It filled for about 15 seconds and then shut off (it's still open now and not running). The pressure gauge didn't move at all. I have attempted to open and close the filling loop a few times and it won't take any more water. I have also fiddled around with outlet valve which seems to open and close normally and the filling loop runs for a moment after I close it and stops of its own accord.

The plumber is coming at the end of the week, but he hasn't experienced this problem before, so I thought that it might save time if he comes armed with the parts. He suggested that the pipe to the pressure gauge might be clogged; would this prevent the boiler from firing? Any other ideas?

Any advice would be gratefully received. Thanks,

Ben

 

[BenHulland]

Oh, I should probably also have said that I checked the expansion vessel and it is at 2.5 bar (and is full of water).

 

[Armo74]

Theres your problem then

 

[BenHulland]

Sorry, that should read: Isn't full of water. It's full of air. Promise.

 

[twgas]

How did you measure the 2.5bar in the vessel?

 

[BenHulland]

With the gauge on a car foot pump into the valve on the expansion vessel (after checking that it was full of air by pressing the valve down).

Thanks.

 

[twgas]

You should only need 1 bar max, in the vessel, did you have an open end/drain valve on the boiler system when you checked it?

 

[BenHulland]

Is that the waste water outlet that runs to the outside? If so, yes, and it runs straight through when I open the valve manually and stops when I let go.

As far as I can tell, it's completely closed apart from that.

 

[Terry lambert]

You need to let the pressure out of the system to test and charge the vessel

 

[BenHulland]

Okay. Do I run the water out using the outlet valve with the filling loop closed and then check the pressure in the vessel? Should I leave the vessel at about 1 bar (can't find the recommended pressure anywhere in the manual)?

 

[hazetimesfive]

if there is pressure in the rads and 2.5 bar in the vessel then i think there could be a teeny weeny fault with the pressure gauge

 

[BenHulland]

I thought as much. What I was trying to work out was if the gauge would prevent the boiler turning itself on, or if it's just for information. I'd obviously like to know what the pressure is, but I'm worried that there are two problems with the boiler.

Thanks.

 

[twgas]

Is there a proper drain cock on the system? If so connect a hose to it and run the other end to a drain,undo tha drain cock to release the water, leave the drain cock open and check the pressure in the vessel

 

[BenHulland]

Hello, there is no pressure at all in the vessel with the drain cock open.