Worcester Bosch 35CDi II - water leaking from top

[bilbo999]

Hi, first post so hopefully somone out there can help.

Here is the history story etc..

I have a Worcester Bosch 35CDi II which we have had for about 5 years, was fitted in the house when we got it. General history is that it has been a royal pain in the rear. Constantly loosing preasure, top up the air tank and water regularly and the pressure will drop back to nothing in a week or so. I suspect more than anything it was the cowboys that built the house and the pipes are probably leaking somewhere.

Anyhow latest problem now is that when the pressure drops I top up the air tank to between 1 - 1.5 bar and the same for the water. What it has now started doing is leaking from the top. I think it is the preasure relief valve. Got a nice brown stain on the ceiling from it. This is now getting worse in that as soon as I re-pressure it, it seems to dump the pressure out of the top and we have water all over the place. Water temp is up and down especially when in the shower, when the water goes hot and cold.

I admit to knowing next to nothing about these and would be reluctant to do anything to fix it unless it was idiot proof. I more want to get an idea if it is terminally ill or possibly a simple fix.

Thanks in advance for any help or advice anyone out there can offer.

 

[kevplumb]

auto air vent

 

[Agile]

I am sorry to have to tell you that the only problem is likely to be what YOU are doing to your boiler.

Only someone who knows how to do it should be pressurising the air in the expansion vessel. There is a set procedure which if not followed is going to make the problem worse.

I think you need a competent boiler engineer !

Tony

 

[bilbo999]

Thanks for the responses, I was following what I had been advised by the people who came out to inspect the boiler when I first reported it was loosing pressure. They advised to top up the pressure via the water fill up underneeth and also to check the air pressure in the cylinder and that could also be topped up to around 1.5 bar.

Is it normal for the air cylinder to drop to 0 pressure. Also if I was to get an engineer out every time the pressure was low they would be visiting every week or so. I have heard these are good boilers, mine just seems to of been installed on a friday afternoon after they had all been to the pub.

 

[Agile]

If the set procedure has not been followed then I cannot guess what yours is doing.

Tony

 

[bilbo999]

What is the set procedure for doing it, the way I was advised to was:

When the pressure gauge on the front of the boiler showed at zero. Check the air pressure on the cylinder and top this up if needed to 1 - 1.5 bar. Once that was done to then fill the water up underneath so the gauge then showed 1.5 bar.

 

[Agile]

With pressure gauge on zero AND the system open to air, pump up air to 0.9 Bar.

Then close system and repressurise to 1.5 Bar cold.

Tony

 

[bilbo999]

Thanks for that, they did not say anything about system open to air. Not sure what you would need to do to enable that.

So the way I have been doing it would that account for water coming out of the valve at the top of the boiler. I know it is sort of a how long is a bit of string question.

 

[Agile]

No, thats another problem. Its leaking and should ideally be replaced.

But for the moment you can screw the cap hard down after any air has been released.

The easiest way to open the system to air is to remove a bleed screw!

Before draining any water have you depressed the pin in the air valve and let ALL the air out first to ensure no water comes out?

Tony

 

[bilbo999]

From what your saying it looks like the boiler is generally OK. Might need the valve on the top replacing and some TLC from decent Engineer. I think I will try and get an Engineer out to give it a service and check over and mention the valve leaking at the top.

Thanks for all the helpful comments especially Agile.