Vaillant

[BSeanB]

I have a Vaillant VC GB 182E - The pressure dial keeps rising - I have checked the mains in and it is closed - I have taken water out of rad and still rises - the hot water in the basin taps is very hot even though only the central system is on not switched hot water on at all

 

[garethdavies]

how old is the boiler?

 

[muggles]

Can you give more details of your system? What kind of hot water cylinder do you have? Are you certain that the filling loop isn't passing (IE, the valve may be in the off position but water might still be getting through)?

 

[muggles]

how old is the boiler?

They were built between 1988 and 1996

 

[garethdavies]

its over 20 years old and replacement is due

 

[muggles]

What rubbish, these are perfectly good boilers and with the right care it'll go on for years. "Being old" isn't a good reason to replace a boiler

 

[BSeanB]

Anything between 16 to 18 years - The boiler can be switched on to CH or Hot water feeding a Hotwater Cyl - The problem occurred when the plumber moved a rad - he had to take some water out of the system - he then refilled it. The pressure dial keeps rising and I have checked the mains water top up to make sure it is closed. As the pressure builds up , the hot water to domestic becomes boiling hot even though I have not switched the hot water system on. Today I left the CH system off and switched on the Hot water - the bar pressure still rose even with the CH system off.

The plumber pointed toward a three way motorised valve which diverts the hot water to either CH or domestic water - he says it switches between the two but it may be faulty.
My feeling is that the input valve from mains is still letting mains water in to bring up the pressure slowly -

 

[lightning]

Filling loop letting by, or expansion vessel needs recharging .
Hot water to hot could be faulty cylinder stat or faulty 2 or 3 port valve

Paul

 

[Bunnyman]

Filling loop passing, or if mains pressure cylinder the coil may have gone, Chk the vessel as well

 

[BSeanB]

The pressure seems to have stabilised at 2.0 - I have had the Central heating only for 5hrs - I will a close eye on it Thank you for your replies - if it is any more complicated I may have to have a new system - expensive option!