Veissmann 100-w F4 error (... trying to follow a youtube video)

[Deleted member 99988]

I have had problems with varying temperature in my shower - the combi boiler would cut in and out when the shower was used. This did not happen on hot taps.

Some googling told me that the heat exchanger might need cleaning. I found the following video:

I think that I have "drained down" the boiler. Lots of water came out of the ?outlet pipe. The pressure gauge kept shooting up whilst I did this which had me slightly worried. The boiler emptied itself of water.

The attached photo shows the position that my valves/taps are in underneath the boiler. I stupidly didn't take a photo beforehand but I think they are in the position they started. I have not touched anything inside the boiler.

My problem now is that the boiler won't reignite. When I use a hot tap or turn the central heating on it keeps trying to ignite. After a few attempts it fails and eventually shows an F4 error. I have switched the boiler off to give me a chance to think.

I know that I shouldn't have been messing around with the boiler.

How can I get the boiler up and running again? (or have I broken something?)

Thank you very much in advance.

 

[ShaunCorbs]

Gas is off turn the yellow valve 1/4 of a turn

 

[Harvest Fields]

Is this a real post?

 

[Deleted member 99988]

Thank you very much Shaun. I misunderstood the markings on the tap.

Are the other valves in the right place?
Do I need to repressurise anything having let lots of water out? Boiler pressure is currently 2 bar.

 

[Harvest Fields]

If all the other hot taps work it will
Probably be a shower issue.

 

[ShaunCorbs]

Did you undo anything inside the boiler ?

And for your info you need to be gas safe to remove the cover

 

[Deleted member 99988]

I did not do anything inside the boiler, just took the front off to see inside.

 

[Harvest Fields]

Was about to type that but you beat me to it.

 

[ShaunCorbs]

What outlet pipe are you referring to ?

 

[Harvest Fields]

I did not do anything inside the boiler, just took the front off to see inside.

Which unfortunately you need to be gas safe to do as the outer case is the integral casing on a Viessmann

 

[Deleted member 99988]

If all the other hot taps work it will
Probably be a shower issue.

Same issue with both showers. One is a thermostatic aqualisa quartz a1, the other is a bristan mixer shower.

I live in a block of 24 flats. I have varying water pressure between 8-16L/min. I bought a weir gauge today to check this. Also checked with several other people in the same block who have a similar problem. We have a booster set outside which has recently been replaced.

 

[ShaunCorbs]

Same issue with both showers. One is a thermostatic aqualisa quartz a1, the other is a bristan mixer shower.

I live in a block of 24 flats. I have varying water pressure between 8-16L/min. I bought a weir gauge today to check this. Also checked with several other people in the same block who have a similar problem. We have a booster set outside which has recently been replaced.

Kitchen tap doing the same ?

 

[Deleted member 99988]

What outlet pipe are you referring to ?

The 2 black valves on the bottom.
I think the far right is open and the second from the right is closed.

 

[ShaunCorbs]

The 2 black valves on the bottom.
I think the far right is open and the second from the right is closed.

So you drained from there ?

 

[Harvest Fields]

The 2 black valves on the bottom.
I think the far right is open and the second from the right is closed.

Then open it mate.

 

[ShaunCorbs]

Then open it mate.

No that's the filling loop

 

[Deleted member 99988]

Kitchen tap doing the same ?

Kitchen tap has same pressure problems but temp does not vary.
I thought it might be the shower(s), but a plumber who came to look told me it will be due to the water pressure fluctuations confusing the boiler.

 

[ShaunCorbs]

Right you need to drain some pressure out of the boiler as it's too high nest way is a cup towel and a rad via the air bleed screw

Your looking for around the 1.25 bar cold or 2.5 bar hot (eg rads on or off)

 

[Harvest Fields]

No that's the filling loop

Thinks it’s both a filling loop and iso

 

[Deleted member 99988]

No that's the filling loop

I also have a separate filling loop which both valves are normally kept closed.

 

[ShaunCorbs]

All the valves look open just do as I've said above then you should be able to turn your boiler back on and check everything's working

I'm off now but will check in tomorrow to see how you've gotten on

 

[ShaunCorbs]

I also have a separate filling loop which both valves are normally kept closed.

Same with this one turn the right one so it matches the left one

 

[Deleted member 99988]

Shaun - the pressure is now set as you advised me. The valves on the filling/iso loop on the bottom of the boiler are closed as you suggested. Ok to leave like this?

 

[ShaunCorbs]

Yep test if you have heating to confirm everything ok

 

[Deleted member 99988]

Sorry for the delay in response. Heating works fine now.

When I first messed around with the boiler, a good few litres of water came out the boiler when I opened the filling loop on the boiler (not the one on the wall).

I figure that I need to replace this. However when I fill it up using the filling loop on the wall (the braided flexi pipe) the pressure goes up pretty quick to 1.25 bar.

What should I do?