Viessman vitodens 100 problem

[Koogatubac]

Boiler had no hot water but heating, fault was diverter valve.

Replaced that, now it fires on DHW however gets up to overheat and cuts out.

Replaced the temp stat however didnt fix the boiler. The old stat probe was thick in sludge, phoned viessman, they recon its a circulation problem and recommend a powerflush.
Anyone have any ideas?

 

[Dotty]

Pump spinning and impellor ok?

 

[Ermintrude]

Blocked hex ? Fill her up with x400 and let it cook for a week. Would also check pump, does pressure skyrocket? Any idea which over heat is kicking in? Main or pipework?

 

[Roger Welton]

Had this before the plate was sludged up.

 

[Koogatubac]

Its had ALLSORTS changed, boss said it was a new pump. Took it off and didnt look that bad, plus it span croppie merchants werent open and didnt have any cleaner, my next thought was either heat ex or pump chemicals in and give it a good flush. On heating its gained to 98* and never overheated, however when i changed the overheat stat on heating it rises to 83* max.

Ive worked on other boilers and they all have dirt in, but i wouldnt of said powerflushing should solve the problem :S

 

[Ermintrude]

I defo clean it's the plate . 1/2 tub of flux is good cleaner when your stuck!

 

[Killy Bing]

Oh you poor soul, although i cant help but smile.

viessmann boilers go hell with a spec of sludge.

 

[Roger Welton]

Which is strange as they claim sludge won't touch there heat exchangers lol

 

[Nostrum]

Haven't had much dealing with them on repairs but didn't rate the vitodens 100 I serviced the other day much, maybe the 200 is a different kettle of fish?

plastic worcester like hydro blocks and the condensate trap was right at the back, awkward to get out etc

looked cheap and nasty really, thought they were supposed to be a reputable boiler?

 

[smhstu]

Have had this once and it was just air in the hex

 

[Koogatubac]

Cheers guys, ill let ya's know what happens when i get hack there!

 

[Killy Bing]

Which is strange as they claim sludge won't touch there heat exchangers lol

On the other hand they say any sludge in the system and they wont cover you.
on training they advice you to repipe system on boiler replacement.

having had a few viessman off the wall and flushed out (over ten) for a previous employer

they fire aggressively and bake the sludge into hard deposits around the hex.

 

[moogwai]

went to a vitodens 100 regular boiler which had been dry firing and this was the out come! Was on a one pipe system with a blockage in it!!

 

[aligorgon]

as previously said is the hex been fully vented. i had this once had to attach a hose and run it outside off the cock.

 

[Rizme]

I have had to deal with this boiler twice and in both case ended up stripping the boiler and cleaning each bit on it. The sludge sticks to every part on it.

 

[Koogatubac]

Cleaned the heat ex today, was absolutely black!! Make a big difference however still overheats eventually, ordered a new heat ex, fitting thurs morning! Keep u guys informed

 

[Koogatubac]

Ok so put in new heat exchanger, hasnt fixed. 5yr old boiler, got longest history of repairs, all parts have been changed some have been changed twice!
Solution - new worcester going in!

 

[Nostrum]

From bad to worse then!

 

[Ermintrude]

The 100 are just easier to replace. Fan, gas valve pcb, sensors thermisters = rubbish

 

[Koogatubac]

Well i have a poor view of them. Every part is easy to change mind compared to some boilers which leave your hands getting chewed off