Topping up a System Boiler

[towser_11]

Hi - I have what I think is called a system boiler that's providing central heating and hot water to a tank in the airing cupboard.

How to I repressurise this?

It's a Worcester Bosch Greenstar 24i but it doesn't have the usual filling key arrangement.

Under the sink near the boiler there's a filling loop which I've opened but the pressure guage doesn't shift and to be honest it doesn't sound like any water is going into the boiler.

I'm a bit stumped so any clue or suggestions are most welcome.

Thanks

 

[towser_11]

This is the underside of the boiler - the red circle indicates the pipe that is connected to the filling loop under the sink. That pipe feels warm / hot to the touch in case that's of any relevance.

 

[terryplumb]

You should have shown us pics of filling loop. What is the actual boiler pressure ?

 

[towser_11]

Hi - thanks for getting back. Filling loop and pressure pictures attached.

 

[Mottie]

Are you opening both ends of the filling loop?

 

[terryplumb]

The black handles should be in line with the pipes for both to be open.
The left one is in off position ,can't tell what position the right hand one is in.
When both are actually in open positions ,if water doesn't flow ,sometimes the black handles do not actually turn the spindle . Remove the handles and try moving the spindle with a spanner.
No pic of pressure gauge ??

 

[towser_11]

 

[towser_11]

Hi - yeah, I'd opened both ends last time I tried (now you have me doubting myself!!) - will double check in the morning and try again. Pressure guage pic posted.

 

[towser_11]

Opened both valves on the filling loop this morning and let it run for about a minute - pressure guage barely moved - picture attached.

Closed the filling loop - so it looks like the loop under the sink does the job but my question is how long should it take to re-pressurise? Any boiler I've had in the past needed only 30 seconds to top up so concerned about just letting it keep filling incase the guage is broken.

This boiler has been fine since I moved in to this house 3 years so it's not been topped up in that period so I've no idea how long it usually takes.

 

[terryplumb]

Leave it open until the pressure gets to 1 bar. At least the loop is actually passing water

 

[towser_11]

Hi - so boiler been topping up for the last 30 minutes or so and the guage has barely moved, doesn't sound like water is flowing into the boiler any more. Picture of guage as it is now. Turned off the loop for the moment.

 

[terryplumb]

Looks like your filling loops check valve is stuck closed and needs replacing

 

[towser_11]

Problem solved - I traced the cold water pipework and found that there was a fill loop on the cold water pipe beside the hot water tank in the airing cupboard. Turned that on and the boiler topped up. Bit random as it's the other side of the house from the boiler itself. So managed to get it topped up in 30 seconds.

I've no idea what the other loop does, maybe it was for an old boiler.