Worcester 240 Combi Boiler - How to "top up" or re

[omara04]

Hi Guys

Long time reader, first time poster, here's hoping you can help me.

I've just moved house and found myself with a Worcester combi boiler, with all up-to-date tests and stickers. (think it was part of a British Gas service agreement until when I moved in)

Anyway, the first night we put the heating on for a "+1 hour" just to check it was OK. And it was, lovely jubbly, nice and warm. Only today when I come to it, when you switch it on, nothing happens. Upon checking the pressure gauge it's right down to zero. No problem I thought, I'll just top it up. Only, I can't find any way to do that? The last combi I had was a Vaillant and it had the mains cold water input with a valve that you just opened with a screwdriver.

Underneath this boiler are 4 pipes - the central heating flow and return pipes, mains cold water in (normally open, and when you turn this valve off the hot water stops working) domestic hot water out and the gas in.

There is a pipe that comes upwards from the top left (facing the boiler) and goes into the loft - that has a red valve like you see on some fire hose reels, and in the loft that goes into a small tank; although it's all covered up with bin bags and gaffer tape. The previous owner mentioned there's a small tank in the loft, but that it was disconnected from anything. (not sure if he knew what he meant?)

Reading the manual it mentions that you have to connect up a hosepipe to the central heating system to top it up, is that true? Or is there just some valve I'm missing to let water in? And could this tank be anything?

Any help appreciated, really would like to fix it myself rather than pay £££ on top of everything else moving house!

Thanks in advance,
Steve

 

[tamz]

The 240 could be either open vented or sealed and as you have said there is a pipe going from the boiler to the loft it may well be open vented. Check the red valve is open. If it is an open vented system, depending on the height of the feed tank above the boiler, the guage will not move much. For it to register 1 bar the feed tank would need to be 10meters above the boiler.
If it is a sealed system there will be a filling loop somewhere not too far from the boiler. Maybe behind a unit below?
Best idea would be to ring the people you bought the house from.

Do you still get hot water? If so then the boiler is working so unlikely to be a pressure problem.
You may just be unlucky and the boiler has a fault.

 

[omara04]

Tamz

Thanks for your post - So this morning I've been up into the loft, and the small tank directly above the boiler is full of water, and the ball/float valve is working fine.

There are 2 pipes that come down from the tank into the top of the boiler, and they "tee" together - one has the fire hydrant type valve on it, the other does not. I'm guessing it's an open vented system, and that this is the expansion and feed pipe?

Had to employ the missus (as she's thinner than me!) to reach down into the tank and feel for the connections, they aren't blocked or filled with gunk.

So there's water in the tank, and I'm guessing water down this expansion pipe, but still no pressure - not even a tiny dribble, the needle is resting on the pin by zero.

As another check I cracked open a radiator drain valve, and there was a very very small guff of air (literally nothing) and then nothing else - no water or anything.Still nothing on the pressure gauge.

Any further suggestions please? Any help greatly appreciated.

 

[omara04]

Ok... Numpty Alert!!

Fixed it. Turns out there was a room thermostat randomly placed halfway up the stair case, must have been knocked to zero during the moving of many items of furniture past it... Radiators are warming through nicely now

Just like to say thanks to Tamz for his quick response, and it's not all bad because I've learned quite a bit about open/vented heating systems.

Thanks!

 

[tamz]

Ok... Numpty Alert!!

Fixed it. Turns out there was a room thermostat randomly placed halfway up the stair case,

Easily done in a new house.

If the header tank is not very high above the boiler the pressure gauge may not register much.
Every 1 metre height above the boiler is approx 0.1 bar.
Don't worry about the gauge.