FOR ATTENTION OF STEVEYBOY

[Galvanised]

Im having the same problem mate , gradually but only when the heating is on the bar pressure on the guage goes up by a tenth of a bar a day untill after 10 days or so its on 2 bar when not heating and 2 and a half when working...no other problems...
I have to bled the radiators and was also told to bleed the one closest to the boiler but to no effect , i get rid of the excess water ( and it is water ! ) by bleeding the bathroom radiator so the boiler goes down to 1 bar again ( this is about 5 litres of water !!!! ) so somehow more water is getting into the system ...but how ???...it is a sealed unit using a key is the only way to fill it..
It cant be air can it ?....im unsure because of the ammount of water i am removing and am worried about calling a plumber and paying a lot of money when it might not solve the problem..

anyhelp out there please...
thanks
gav

 

[oilman]

Need to know what make of boiler.

It could be a possible leak through the inlet valve, but the gas boys will be able to give you more help.

 

[Galvanised]

sorry oilman...its a worcester 28cdi....been looking through the threads and i think it could be the expansion tank by the sounds of it...but steveyboy has the same prob and replaced his to no effect so im like 60-40...i know the presure relief valve kicks in at 3 bar so i always bleed at 2 and a half..

when the boiler was insatalled it was set at 1 bar and the red dial was set at 1.5 bar to show how hot it would get when working and it was exactly like this for about the last 5 years..last 6 months this has been happening so something has gone t*ts up...

 

[oilman]

That's some good info. I don't know anything about the boiler, but the expansion vessel? At 5 years, that's old. If you can find a dust cap on the tank, on a car tyre type valve, take it off and depress the valve. If water comes out, it needs changing.

 

[breezer]

Galvanised, you must apreciate how these forums work.

you posted F.A.O steveyboy, steveyboy only joined on 15th December, made 3 posts on the same day and has never returned, if you look under a posters "name" you will see how many posts they have made, a very low number indicates they do not post often and in all probability are unlikely to post again.

listen to what oilman says you will be taking good advice

steveyboys' posts are here

 

[oilman]

listen to what oilman says you will be taking good advice

Are you kidding? here's me going to work

Would you like some more advice?

 

[Scoby_Beasley]

AAAAaaaah ! So you like the suit then ?????

 

[ChrisR]

Gav the oressure vessel won't be "making water"! If ithas no pressure or is full of water, expansion water will drip out of the prv pipe and you'll have to fill er up when cold. 1 bar is normal when cold.

Unless your combi is heating a hot water cylinder the only way for water to get in is through the filling arrangement. These boilers use a big plastic T shaped thing which shoves in from underneath. . IT MUST be removed.

There's no other way in - the T thing actually forms part of the waterway into the boiler

 

[Galvanised]

Chris , i understand how water must enter the boiler using the t piece to fill it , i have filled it many times wgen i have removed radiators to decorate , what my point is , is that i am removing at least 10 pints every 10 days and the water pressure on the guage returns to 1 bar and the system works perfectly ( heating and hot ( scalding ) water immediately ) so why am i removing water !!! like i said this is a weird one...was thinking about getting GASCARE or something similar and letting them sort it out after a few months as it is not a disastrous problem and can live with it just a bit of hassle bleeding that rad every 10 days to relieve the pressure...

you know the pressure guage on the front is this directly linked to the expansion tank? if so then the pressure in the tank is rising somehow....baffling for me but i may be good at diy but im no plumber..!!

cheers everyone for your help..

 

[COG]

Just spotted your thread. If your pressure rises without the filling key fitted and it does not come down when cold then its your water to water heat exchanger passing, thats not just a guess, you need to replace it and check your mains pressure is not above 10bar ,best check in the early hours say 3am when the pressure is the highest. the plate is only tested upto 10bar. Worcester have a set price for changing heat exchangers its £210.00 inc vat. PS the heat exchanger is guaranteed for 5 years but only against lime scale

 

[Galvanised]

Thanks for the reply so quick Cog , im going to check the expansion tank 1st by opening the valve to see if air or water comes out ...if its ok then i guess a trip to the phone for a plumber...ouch..

 

[COG]

If your pressure vess was faulty your pressure gauge would rise when in CH mode and if turned off at say 2 bar would fall back down also you would have no problem when the boiler was off. if you want to test your pressure vess then befor you drain down check you can get a tyre gauge onto the tyre valve on the vess its often too close to a pipe,since the cdi has been on the market i have changed at least 20 w/w heat ex and only one pressure vess

 

[Galvanised]

Thats what is happening , the pressure guage is rising only when the heating is on....during the summer it hardly rose but now in the winter more heating and it rises every day...it doesnt rise when ithe heating is off......the rise is not noticable when watching but more of a gradual creep over a 10 day period of about a bar..

cheers for the reply