Valliant Turbomax Plus 242 / 824 E - low hot water pressure?

[Pattrickk]

Hi there,

Hope you guys can help! Been lurking for a while and you guys offer loads of knowledge and advice, but something I can't seem to find generally is the above boiler. I've been in the property for a month now (and it was NOT looked after. Gas man reckoned it hadnt been serviced since installation ~12 years ago) Anyways Ill add some images to show what I'm talking about. But the pressure on the front of the boiler when its not heating the house is always at 0. When hot water is running I cant say I've noticed in go up. When the central heating is on it reaches between 2 and 3. Now I know theres meant to be a hose type thing underneath but theres just a white knob which clicks when i turn it anti clockwise and doesnt seem to change anything and is too stiff to turn right. What am I looking at and how can i fix it?!?

Thanks guys!

http://imgur.com/CspCW2A Boiler front / no pressure
http://imgur.com/gYA3hJQ Most of the piping underneath
http://imgur.com/ivRY4tr The problematic white turny thing (so technical!)
http://imgur.com/ZyhijrT Something coming out the bottom?

 

[Pattrickk]

Once I turned it a couple times and had the central heating the pressure only goes to about 1 now so maybe this is connected? Hope someone can help!

 

[ianmcd]

Afraid only 1 of your imgur links is working,it sounds like you need to re-pressurise your expansion vessel it tell you how to in the FAQs on here but you must follow2 all the steps, a 242 and an 824 are two different boilers you need to check which one you have

 

[Pattrickk]

Afraid only 1 of your imgur links is working,it sounds like you need to re-pressurise your expansion vessel it tell you how to in the FAQs on here but you must follow2 all the steps, a 242 and an 824 are two different boilers you need to check which one you have

They're all working for me? And where would I find that from?
behind the control panel it says both where should I be looking.

Heres what the sticker says:
http://imgur.com/DGBMMV8
As you can see it says both 242 and 824 inside. Thanks!

 

[ianmcd]

This is what you need to do

//www.diynot.com/wiki/Plumbing:faq7

Follow ALL the steps if you try to take short cuts it will not work

 

[Vaillantman1997]

Hi,

Firstly, the appliance you dealing with is either a turboMAX 824/2-5 or a 828/2-5. Both will suffer the same symptoms of a flat expansion vessel which should be dealt with by following the great instructions given above.

One thing I'll mention about the instructions tho, don't always assume that just because you've had water squirt of out of the Schrader valve that the diaphragm is split and the vessel is faulty, you can get quite a bit of moisture in the "dry" side of the vessel which can appear to be water when dealing with a flat vessel.

I've dealt with Vaillant appliances since 97 and only ever change 2 exp vessels to to diaphragm failuers!