Viessmann Vitodens 100 Boiler Not Working - Reset Light

[KOM]

I have a Viessmann Vitodens 100 Boiler that provides heat and hot water. We are getting neither at the moment - the reset light is flashing red on and off and the pressure is showing at 0.5.

Is there a way to fix this ourselves or should I call someone in?

 

[GPlumb]

Use the filling loop to increase pressure 1-1.5 bar, should be a braided hose under boiler somewhere with a small tap on it. Check the boiler instructions too.

 

[KOM]

Thanks Graham. Is this something that the average person can do? I admittedly have no knowledge or skills in this area...

 

[OilLecky]

Sorry for butting in Graham.

KOM Yes you can do it yourself. Find the (hopefully) braided flexible pipe. This is the filling loop. It should have an isolation valve at both ends, one from the rising cold water main and the other into your pressurised system. First find these things. The valves often have little plastic levers that are at 90 degrees to the pipe when closed and in-line with the pipe when open. Then you open the valve at the pressurised system end if it isn't already open then, while watching the pressure gauge, slowly open the isolation valve on the rising main end. Let some water in then close the valve to let the gauge stabilise. Repeat until you get to the required system pressure which as Graham said is normally 1 to 1.5 bar. If you have difficulty watching the gauge and operating the valve at the same time, get an assistant to do one of these things for you. Good luck!

 

[Silvanus]

Many thanks from me too! From reading your guidenotes I've realised that 0.4bar means the water pressure is way too low and then remembered it's ages since I've checked the gauge! Hey presto! - flashing light now magically gone out and boiler boiling away again!

 

[gusone]

Sorry for butting in Graham.

KOM Yes you can do it yourself. Find the (hopefully) braided flexible pipe. This is the filling loop. It should have an isolation valve at both ends, one from the rising cold water main and the other into your pressurised system. First find these things. The valves often have little plastic levers that are at 90 degrees to the pipe when closed and in-line with the pipe when open. Then you open the valve at the pressurised system end if it isn't already open then, while watching the pressure gauge, slowly open the isolation valve on the rising main end. Let some water in then close the valve to let the gauge stabilise. Repeat until you get to the required system pressure which as Graham said is normally 1 to 1.5 bar. If you have difficulty watching the gauge and operating the valve at the same time, get an assistant to do one of these things for you. Good luck!

Brilliant worked a treated for my Viessmann Vitodens 100 Boiler.

I uploaded a picture to remind myself when it happens again and help others below.

 

[Agile]

That does not look anything like the Vitodens 100 boilers which I repair !

Is it the very recent new model?

Tony

 

[gusone]

That does not look anything like the Vitodens 100 boilers which I repair !

Is it the very recent new model?

Tony

Yup. 1 month old. Vitodens 100-W WB1B 26kw Combi with Digital time switch

 

[Agile]

The installer should have instructed you in setting the controls and repressurising.

If it continues to lose pressure then there may be a leak somewhere.

About 1.0 - 1.5 Bar top up every three months would be about the maximum pressure loss to consider acceptable.

Tony

 

[gusone]

The installer should have instructed you in setting the controls and repressurising.

If it continues to lose pressure then there may be a leak somewhere.

About 1.0 - 1.5 Bar top up every three months would be about the maximum pressure loss to consider acceptable.

Tony

Ta. I am presuming the pressure fell to zero because I had removed a radiator and put it back on and then removed another all for decorating purposes. Once I put the other rad back on I'll keep an eye on it.

 

[juliettefournier]

Came home to find our boiler reset light flashing away, couldnt get anyone out for a couple of days then came across your forum. Thank you all for your help, within a couple of minutes i had hot water and heating pure heaven !!!

 

[mysteryman]

The latest model is the Vitodens 100-W type WB1C.

The Vitodens 100 type WB1A [2005-7] had a digital pressure readout. You need to turn both control thermostats on the boiler fully anticlockwise to read the system pressure.

 

[Bandearg]

I am having a similar problem after decorator removed radiator but my set up looks different to above

 

[Agile]

There no filling loop in your picture. Presumably it is somewhere else!

Others may have very negative comments on how your pipework has been installed.

The installer is meant to instruct the owner on how to repressurise the system.

Tony

 

[Bandearg]

Maybe it is beside the hot water tank? Couldn't get anyone out over the weekend and seems like similar problem so thought I'd try remedy it myself as pressure is too low. Thanks anyway