How to repressurise a Worcester Bosch Greenstar 15i Erp

Hi,

Our Worcester Bosch Greenstar 15i erp combi boiler has lost all its pressure. We’ve not bled the radiators and don’t know if there’s a leak (nothing obvious). It’s less than a year old so I just want to try to top it up and see if the pressure drops again.

I really can’t see how to repressurise it. The manual doesn’t say. There’s a label on the boiler saying to take a look at their YouTube videos. I’ve done this but still can’t figure it out....

According to their YouTube videos there’s three options - key, hose or blue valve on the underside of the boiler. But when looking at our boiler there’s a space on the lid for a key but no key, there’s no hose and no blue valve.

Does anyone have any tips or know what I’m missing?

Thanks

 

Its not a combi , its a system boiler, somewhere around exposed pipe area will be a filler loop to re pressurise system.

 

Go to where your HW cylinder is ans see if there is a small usually red expansion vessel there and a pressure guage,if there is your filling loop will be in there , if you cant work it out post a pic of the setup in there and we will be able to tell you what to do

 

Thanks for the info. That’s very helpful. There is a white vessel near the cylinder. I can’t see a pressure gauge in there but there is what looks like there could be two valves/taps along the pipes?

Does the pressure gauge on the boiler still mean anything? To be honest, I can’t remember what I was told about it when it was installed. I wonder if this boiler gauge is irrelevant now?

I only took a look at the pressure as the boiler made a slight vibrating noise. Everything else seems fine so maybe it’s running ok?

Thanks

 

That’s an unvented hot water cylinder. I can’t see a filling loop anywhere on that install, but there should be one somewhere. Sometimes if they are left connected, it’s a silver coloured braided hose. What should the pressure on the gauge reading/photo?

 

Now you have to play hunt the filler loop.

Andy

 

Where’s the boiler located? If it’s in a kitchen, then check in one of the cupboards. What’s the 15mm pipe connected to that runs up the back of the boiler?

 

Thanks for all your replies. I’m out at the moment but the boiler is in the utility and the hot water cylinder is on the landing.

There’s no sign of a filler loop...I’m used to topping up the water on combi boilers but not this type of system.

I’ll have a proper look later when I’m back.

The only gauge that I can see is on the front of the boiler not in the hot water cylinder cupboard. This gauge is like the combi boiler gauges. It’s on zero now and green is about 1 to 1.5 bar.

Is this boiler gauge even relevant if it’s not a combi boiler set up? The label on the boiler is arbitrary and seems to signpost to their YouTube videos and top up with water like it’s a combi boiler but there’s no way that I can see to fill it! No loop, no key and no blue valve. There’s a space for the key under the boiler flap but no key and nowhere to put the key!

 

The gauge is relevant as it’s a sealed system,as is a combi boiler, the combi boiler does heating and hot water all in one unit (combined - hence the name), a system boiler does the hot water indirectly via a cylinder but does away with the f&e cistern in the loft. Your setup is an unvented cylinder which has an expansion vessel so no need for a cold water cistern either as it is fed from the mains.

So to get back on track, you will need to find that filling loop. As for the manual, page 36 section 6.2 should explain how to fill the system. As I said,try that 15mm pipe that runs down the back connected to a heating pipe.

 

Thanks for pointing me in the right direction. It’s a bit over my head and a friend is going to come over to take a look. Cheers

 

Thanks very much for the info in this thread. It wouldn't have occurred to me that the hose would be so far away - my boiler is ground floor, the airing cupboard is first floor. Nice warm radiators again