worcester bosch pressure dropping

[itsabreeze]

Hello and help please lol!
I have a worcester bosch 30 si. it was fitted in nov 06 along with 1 new rad piped to a ground floor extension and fed from an upstairs rad. System piped in 15mm and microbore. I 1st noticed a leak from the new rad which turned out to be an o ring on the blanking plug at top of rad.
After the plumber fixed this I then noticed that the new rad did not get hot at the bottom and also that the system started to lose pressure every couple of days.
Plumber returned and said air in system and incorrect balancing of rads to blame. ( i thought sludge in bottom of rad but with other rads off the whole rad did get hot)Does this rule out sludge?
He said he had balanced the system and to keep an eye on it

during the next 24 hours the pressure kept falling just into the red so i refilled the system 4 times to 1.5 bar approx, each time a 5 second burst of filling was required.

Next day pressure in the red again!!

searched around and found 1 lockdown valve leaking at the gland tightened and stopped leak.

Again, next day pressure low, topped up twice.

Why is this happening? IS it likely to be another leak? Is there any other way to explain this? please help as the plumber seems to just want to fob me off. Could the boiler be faulty? many thanks in anticipation

Regards Andy.
p.s. since new boiler was fitted we get a scum forming on the top of drinks, tea , coffee etc.
Is it possible for water from the radiators to pass into the domestic water supply?

 

[gas4you]

As a general rule cold at bottom is sludge, cold at top air.

Have you checked the safety discharge pipe out side for dripping etc?

if you can find no leaks anywhere then perhaps a warranty call to worcester is called for.

What pipe do you have in floor? if any were these air tested before filling up? You could have a leak underfloor that is not showing.

Fill system to about 1.5 - 2bar and turn off heating isolating valves for about 2-3 hours. if pressure does not drop then boiler is ok and must be leak in existing pipes

last ps, shouldn't be possible on new boiler.

 

[itsabreeze]

I have noticed the occasional drip from the open ended pipe outside that comes from the boiler. but i wouldn't have thought enough to warrant how much filling i have done?
Are the heating isolation valves in the top of the boiler or are they just above the boiler in-line?
I have looked at the new joints under the floor where speedfit was used to add new rad and at least this seems a sound joint.
No signs of leaks anywhere on walls or ceilings as yet but am still looking for them to appear
All assistance and opinions gratefully received,
Andy.

 

[gas4you]

Speedfit under the floor? I hope this is wooden and not screed

You should not be getting any drips out od the safety pipe. perhaps boiler is over heating/pressurising for some reason and letting a lot of water out at once, then all you see are the remaining drips? Is there a large wet/damp patch on floor or wall under it?

Don't forget that you will need to replace your inhibitor with all this topping up you are doing

 

[itsabreeze]

the speedfit is feeding the new downstairs rad from bedroom upstairs.
the pipe i have noticed drips from is a 15 mm copper one that comes from the boiler and sticks out about 2" from the wall and then turns back towards the wall. Is this the safety pipe or condensate drain?

 

[gas4you]

This is the safety pipe. Condensate pipe is plastic overflow pipe under boiler

 

[itsabreeze]

thank you very much Dave!!
i have a few things to try now that i can then take back to my plumber.
Finally is it possible for ch water to bleed over into domestic supply or not?
thanks again

 

[gas4you]

It would be possible if the dhw heat exchanger is faulty and leaking and although nothing is impossible it is highly unlikely in a boiler this new, even though it is a worcester!

On a side issue was/is your installer fully registerd with CORGI etc?

 

[itsabreeze]

reason i ask is that since fitting of new boiler we get a brownish scum on top of drinks.
boiler is now upto just under 2 bar and not working hard....have arranged a container to catch any potential outflow from safety pipe....this sounds possible as i have seen the boiler operating on the cusp of green and red at the top of the safe pressure markings of gauge. Should i also be getting much steam from the flue?.... sorry must be driving you mad now yes installer fully reg and sent of all benchmark paperwork to bosch ....do you not rate worcester bosch then?

 

[gas4you]

What looks like steam from flue is good. I always tell my customers as a general rule the more steam you see the more money you are saving as this shows the boiler is condensing more!

This is not always visible, it will depend upon weather conditions and temp outside, also whether the boiler is 'flat out' or 'ticking over'. Therefore somedays you may not see much others it could lokk like a fog! Both normal!

Boiler system pressure should be at 1 bar cold, rising to around 2 bar hot. If it is 2 bar cold then over pressurising could result causing the problems you describe.

Worcester have a very loyal bunch of supporters and installers, but unfortunately I am not one. This is only my personal observations so don't worry about it!

Glad to here your boiler has been registered etc correctly.

The brownish scum? Are you using hot taps to make drinks?

Cold taps should not be affected by any work to heating system/boiler. Has there been any work on your water mains locally recently?

Did installer fit any type of scale reducer to cold mains inlet on property? I don't know where this is coming from!

 

[itsabreeze]

the steam situation looks as you describe it...perfect....i will look forward to seeing if the boiler does go over pressure, and if it does, calling worcester in.
how harsh should i get with my plumber to get this sorted?
i keep reading how topping up introduces ""HIGHLY CORROSIVE " AIR INTO THE SYSTEM WHICH CAN SERIOUSLY REDUCE WORKING LIFE"
ALL THIS BAD INFO SCARES ME SHI.. ..A LOT LOL not to mention the lack of sentinel inhibitor.
you have been most helpful and very patient thanks

 

[itsabreeze]

almost 1 litre of outflow from safety discharge pipe outside.....what could be causing this?