viessmann 111: hot water issues

[Ted808]

• :uhoh2:
  
  Anyone know the ins and outs of this little boiler?
  
  Cust has HW issues, basically, ?? dirt in the system diagnosed by Viessmann, since then had power flush of CH system but not boiler! (installer back to do this- plonker also had put MF on flow!) Had P2P changed twice, (once me and once Viessmann) and has had Mag filter corrected but, still hot water poor performance - she called me to flush the "hot water side of the boiler"
  By poor performance I think she means; is that there's not enough hot water... and there should be 18l a minute.
  So, now I'm thinking it's not the boiler- maybe the taps/shower, or if it is the boiler the main heat exchanger blocked- the P2P didn't seem that bad when I took it out. (the 1st one)
  All suggestions appreciated.
  • unk:
  
  
  
  
  

 

[Aquazone]

I would check main F&R to plate and see what temp differential you are getting, also isolate Cw into boiler and check no hot water coming from taps, adjust showers and mixer taps to see if it's passing when set to a certain position

 

[SmokeyJ]

Not familiar with Viessmann's, Aquazone's advice sounds a good starting point. Another thing to try is to cut the hot water outlet below boiler and run into bucket. Check flow rate and temp. Will tell you if it's an issue with the boiler.

 

[Ted808]

Thanks yes i agree Aquazone's good start! Thanks SmokeyJ

 

[Ted808]

Just an update. Flushed boiler only, cleaned mag filter and then had a differen fault! F4 which is ignition/ gas/ flue/ condensate. All checked and OK. Called Tec sup Viesman and they sent an engineer a few days later. He spent over 6 hours wrestling with it and now it's been working since!!! So no idea then?! :banghead: