Empty some water from Combi Boiler but how?

olliewb

Can anyone help me....

I have a Worcester 28Si Combi Boiler, currently the pressure is 3.5 (max is 4) and water is continually dripping from the over flow pipe.

I thought it best to just empty some water from the system but HOW??

I know how you add water to the system but dont recall how you drain some from the system. I know there is a small plastic tube hanging down from under the boiler (approx 6 inches long) which I seem to recall you can use to empty into a bucket.

Underneath the boiler there is a silver tube containign the water, I know you use the valve on the left to add water to the system but do you use the value on the right to empty?? It doesnt appear to be a normal type valve but one you might need to use a screw driver to operate??
(it is a large black circle)

see a pic I have taken at

http://
img94.imageshack.us/img94/4240/photool.jpg

any help greatly appreciated

thanks,
Ollie

1984ReturnsForReal_2

The valve on the right is a double check valve to stop contaminated water going back into the mains supply from your boiler.

Dont disturb it.

Best way is to bleed a rad I would of thought.

But I am sure the boiler experts will correct me if I am wrong.

I dont think this is why its "overflowing" though.


Where is the over flow pipe?

baldelectrician

I would suggest bleeding a couple of radiators in to a cloth or kitchen roll. It will take slightly longer this way, but will be less problematic

Best not to interfere with the boiler.

There is a way at the boiler, but you may cause something untoward to happen.

davethetaller

Just try bleeding the radiators first, that will drop the pressure.

kaya

bleeding the rads will drop the pressure,
http://www.worcester-bosch.co.uk/homeowner/literature/discontinued-boiler-literature/discontinued-gas-boiler-literature/28si-ii-discontinued-june-2007-literature
or follow the link, you want the pressure relief valve , picture 4 shows the pressure releif pipe on your boiler, there should be a relief valve on it somewhere

1984ReturnsForReal_2

kaya wrote: »

bleeding the rads will drop the pressure,
http://www.worcester-bosch.co.uk/homeowner/literature/discontinued-boiler-literature/discontinued-gas-boiler-literature/28si-ii-discontinued-june-2007-literature
or follow the link, you want the pressure relief valve , picture 4 shows the pressure releif pipe on your boiler, there should be a relief valve on it somewhere

According to this literature the MAX PRESSURE IS 2.5 BAR

Which would be why your system is dumping water.

Did you fill it up to 3.5 Bar?

If you didnt you need an engineer out to sort the real problem.

keystone

olliewb wrote: »

Can anyone help me....

I have a Worcester 28Si Combi Boiler, currently the pressure is 3.5 (max is 4) and water is continually dripping from the over flow pipe.

I thought it best to just empty some water from the system but HOW??

I know how you add water to the system but dont recall how you drain some from the system. I know there is a small plastic tube hanging down from under the boiler (approx 6 inches long) which I seem to recall you can use to empty into a bucket.

Underneath the boiler there is a silver tube containign the water, I know you use the valve on the left to add water to the system but do you use the value on the right to empty?? It doesnt appear to be a normal type valve but one you might need to use a screw driver to operate??
(it is a large black circle)

see a pic I have taken at

http://
img94.imageshack.us/img94/4240/photool.jpg

any help greatly appreciated

thanks,
Ollie

Do it via the rad - just let some water out. DO NOT touch the PRV - its automatic and it is that operating which is causing your "overflow". They are set to iro 3 bar to prevent the system overpressurising.

Your system pressure is obviously too high. It should be at betwen 1- 1.5 bar when cold and 2- 2.5 bar when hot as a rule of thumb.

One basic reason that this can occur is that the filling loop has been left connected and the valve not closed properly so the system continually tops up. The filling loop is your "silver tube". Your link doesn't work for me but from 1984 description he is right you have a check valve to prevent backflow and this is not adjustable. The inlet valve at the other end should be shut off and the loop disconnected. Make sure you have all valves associated with the loop closed. Otherwise you'll get more water than you brgained for - either from the mains or out of the boiler. I'll try and make your link work for me again when I get back from a short outing then I'll be able to see what you have for sure.

Another possibility is that you have an issue with your expansion vessel. Either it needs recharging or the diaphragm is knackered. How old is the boiler?

First things first though. Let some water out to reduce the pressure and the PRV will stop operating and second make sure your filling loop is off and disconnected.

Cheers

Edit: You'll find all information about the filling loop including connecting and disconnecting and the correct pressures in your boiler manual.

AGBAGB

How did it get that high?

If you have overfilled it to about 3 bar when cold, then bleeding a few pints off a radiator to bring it down to (check your manual) about 1.3bar, should work.

If you filled it to the right level and it shoots up when the boiler is firing then somethings up with the expansion vessel.

If so it might just need pumping up, more likely if it's a sudden problem it will need replacing.

A short term fix may be possible if you need it

keystone

Got the link to work but the image is very indistinct so can't tell much from it. That on the right looks like a non-return valve but I'd be sticking my neck out to say that it was for certain and that on the left looks as though it has a lever on it. If it has it looks closed but again very difficult to tell for certain from the image provided.

Have you ensured its closed yet and have you released pressure from the system via a rad?

Cheers