Worcester Bosch 28cdi boiler releasing steam

adam787_1

Hi all,

I have a Worcester Bosch 28cdi, it works fine for most of the time but every now and again (once a month) the Rads and hot water stop working and the boiler releases lots of steam from a small valve at the top. That normally goes on for a few mins the lights flash on the boiler, I then press the reset button and everything seems to start working again. There doesn't seem to be any problem with the pressure in the system.

Any ideas why this is happening?

Thanks in advance.
Adam

ormus

it will be a safety feature/device. when the water temp or pressure get too high, the system will shut down and let the heat/pressure escape safely.

then u need to hit the reset to kick start the thing off again.

Canucklehead

Hi

You have a serious overheat problem.This would be due to pump failure or no circuit for the water to go around. Don't know why it would only happen randomly.

Do all your rads have T.R.V s on them?
Intermittent failure of diverter, pump, boiler thermostat, or other component impossible to diagnose without being there.

Corgi Guy.

adam787_1

Canucklehead wrote:

Hi

You have a serious overheat problem.This would be due to pump failure or no circuit for the water to go around. Don't know why it would only happen randomly.

Do all your rads have T.R.V s on them?
Intermittent failure of diverter, pump, boiler thermostat, or other component impossible to diagnose without being there.

Corgi Guy.

Hi Corgi Guy,

Thanks for the reply.

All my rads have TRv's and all are on all the time and heat up fine. Do you think its worth doing a pre-emptive strike and take out boiler cover ready for an imminent breakdown?

Cheers
Adam

Canucklehead

Hi


If all you T.R.V.s are closed down ,or nearly closed down. then there is not enough circulation and the boiler could overheat.This could explain the random problem.
Does it happen after the heating has been on for some time?
The best set up is to have the radiator nearest the room stat (if you have one ) with no T.R.V. Leave that one fully open,(or take the head off .)
Corgi Guy.
PS leave the cover on for now!

adam787_1

All the TRV's are fully on and the rads heat up with no problems, I think it does happen after the heating has been on for a while.

Canucklehead

Hi

Not sure what else to suggest !
Does your hot water run out of the tap 'cloudy' ? Fill a clear container and see.

Corgi Guy .

adam787_1

Yes it does some times, thanks for all the advice here, I think I am going to go for the N-Power boiler insurance in case it goes again !

Canucklehead

Hi

I would guess that you live in a hard water area, and that you have the heating thermostat on the boiler turned up to somewhere near max?
I would also suggest that the problem might be a blocked heat exchanger,maybe both or at least the secondary one for hot water (plate to plate).
You don't mention if you have a room stat. If not then I would highly recommend one .
Just out of curiosity you could try running the central heating.Watch the boiler, and when it gets to temperature and cuts out, run a hot tap..

It might take some time to work out what the problem is ,so getting insurance on it would be a good idea.
Good Luck
Corgi Guy.

silvercar

can I interrupt with a question?

we recently had the heat exchanger replaced on a two year old boiler due to the pressure rising when the heating came on and the safety valve releasing steam.

now works fine but I have noticed that the water from the hot tap nearest the boiler is cloudy. we do live in a hard water area but this is the only tap that is affected. The water also runs slowly after about 10 seconds and you need to turn the tap further on to get more water. only this tap is affected.

Canucklehead

Hi silvercar

If you have had a heat exchanger replaced once then you are likely to lose another one, unless you fit some kind of scale reducing device. A lot of the boiler makers recommend them. (although some now say you don't!!) Mostly they will be the magnetic type that either fit in the pipe going into a combi or a wire wrapped around said pipe. They have a plug/transformer to go into a socket.
As for the tap.I think I know what you mean, the tap has a mind of it's own and slows down while you use it!? This is cured by stripping down the headworks, cleaning the old grease off and re grease using silicon grease.(I have some I picked up in a merchants that is suitable for steam! Swan is the name (American.)
H.T.H.

Corgi Guy.