1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Discuss Viessmann 111W storage combi "Crinkly/corroding hoses" Your advise/experience in the Central Heating Forum area at UKPlumbersForums.co.uk.

  1. Gerry8

    Gerry8 New Member

    I'm new on this forum so my apology if this is not the correct etiquette. Earlier I thought I was posting this question on a forum but think I actually "started a conversation" with Scott)

    I am looking for advice on Viessman 111W corroding hoses.

    I currently have a 19 year old Baxi Maxflow combi which, like the Viessmann 111W, has an on board ~ 50 Litre storage cylinder. As a concept it works well for us as we understand it. It needs replacing so I looked for a similar system and came to the Viessmann 111W. All was going well and then one plumber mentioned the “corroding rubber hoses” on the flow and return. Long story short, after investigations and mentioning this to a few installers a number of them had seen the issue or had mates who had seen the issue. (coincidentally I was speaking with a man I met and he has a Viessmann system boiler which after 2 years had exactly that problem too).
    I spoke with Viessmann who were quite defensive on the subject blaming the installers for not installing the boilers correctly (blamed it on too much inhibitor!). The chap I spoke to then admitted that they had now changed from rubber hoses but said the 111W still had one rubber hose left in it. All this rather put me off Viessmann as the attitude seemed strongly to be: “we’re right everyone else is wrong”. (I have seen this with some other German suppliers suppling into the UK market where things may be done differntly to Germany). I also heard that their spare parts such as circuit boards are very expensive (I heard a tale of one board costing £950!).

    However the modulation range of the boiler is great, the guarantee of up to 10 years is good and the stainless steel HEX attracts me.

    But I am still very nervous about
    1. Corroding hoses,
    2. The price of the spare parts,
    3. Viessmann’s attitude/interpretation to the application of the guarantee (seem to have a reputation of trying to blame installers and not honouring it)
    Would any of you have any advice/experience to confirm my thoughts or to disabuse me of them?

    Thanks Gerry
  2. Rob Foster

    Rob Foster Top Contributor!!

    Its easy Gerry, if you want this boiler and you have carried out admirable reasearch..you have taught me something. Then re engage with the Germans and see if they will cover these specific parts well over and above their normal statutary
    time...nothing silly, say 8 years
    might be appropriate in my opinion...or you can stick it on BG and after a service call they will pick up the tab. I for one will be very intrested in their reply ...you are an astute genuine customer who wants their product ..let us know how it all goes
    Rob Foster aka centralheatking
  3. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

  4. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    1, they dont corrode but oxygen is absorbed through the hoses this reacts with the heated water and a thin lining of crud ( for want of a better word ) forms on the inside . Its when this breaks off it can start to to block the plate heat ex. However they are pretty easy to clean if incorporated into a yearly service.
    2, its very rare you will need any , pretty sure you can get a 10 year warrenty on the 111’s now .
    3, the hose problem has been with the Viessmanns for years now , they bloody well know about it , recently they have changed to copper in some of their boilers after pressure from us guys .
    4 lol , all the above would never stop me buying one , I have just bought a new one for my new house.
    • Winner Winner x 2
    • Agree Agree x 1
    • Informative Informative x 1
  5. Rob Foster

    Rob Foster Top Contributor!!

    What better an endorsement than TFJ...he knows his stuff
    Rob Foster aka centralheatking
  6. Gasmk1

    Gasmk1 GSR

    thought it was rubber only on the 050 all the rest metal.
  7. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    Yep , but I think op is correct theres still a rubber one in the 111, but tbh I haven’t seen one for ages .
  8. Rob Foster

    Rob Foster Top Contributor!!

    Maybe its a rogue one , brand new but a left over that they are trying to dump the op could
    ask for its registration/build id
    before he gets involved
  9. Drewy

    Drewy New Member

    The 111 does have at least the one rubber hose. Viessmann are technically correct regarding the installation problems causing crunchy hoses but it’s not an easy thing to avoid on an existing system.
    My advice is to properly flush the system making sure there’s no cleanser at all left behind and stick with fresh water only, Viessmann don’t push the use of inhibitors. I fit Viessmann, don’t use inhibitors and have no trouble.
    Oh and if on the yearly service the hose is found to be crunchy don’t squeeze it with the boiler running but drain the thing, remove the hose and clean it out, an easy job.
    • Agree Agree x 1
  10. Millsy 82

    Millsy 82 Plumber GSR Top Contributor!!

    Sounds to me like if you went for the 111 you wouldnt trust it or trust viessman to carry out the warranty on it.

    I think viessman boilers are well made but I dont like rubber hoses in boilers and I dont like the price of parts either as they are very expensive.
    • Like Like x 1
  11. Last Plumber

    Last Plumber Trusted Plumber GSR

    Vaillant had a similar issue with crunchy hoses and they replaced them with copper, although you can still by the replacement rubbers. That could also break off internally and lead to a blockage in the main heat exchanger.
    • Like Like x 1
    • Agree Agree x 1
  12. Gerry8

    Gerry8 New Member

    Many thanks for taking the time to reply TFJ
    1. If it's O2 entering the system that causes the crud to form, why are Viessmann so against adding inhibitor, which should reduce the effects of O2, I would have thought. Seems odd?
    2. I wonder why in the 111W they left one rubber hose in but changed the other and changed from rubber hoses in their other models? I assume they really must need a flexible connection in that position in the 111W for some reason and couldn't get around it - does anyone know know if it's the flow or return hose, or which hose is still rubber in the 111W?
    3. You're right a 10 year guarantee is available, at an extra cost, but from what I have heard they do a lot of wriggling to avoid paying out on it. All manufacturers can do this, and on occassions do so, I understand that. For eg the manual states things such as: "Expansion vessels must be filled with Nitrogen". Does anybody actually do that?
    They say water with more than 300 ppm hardness must be softend- how does anybody fill a system with softend water in a house with no water softner? Does any plumber carry a supply of treated water to fill the CH sytem?
    It's always hard to tell what is fair about guarantee enforcement when you only hear only one side of the story from those that have had problems. One chap I met has had serious problems with Viessmann honouring the guarantee and he struck me as an honourable and reasonble man and a very competent heating engineer) and it's a fair view of them I'm trying to judge. Troble is one gets a "flavour" about somethng and its hard to shake of:-( But I like the spec of the boiler​
    4. Glad to hear that you fitted a Viessmann yourself, somewhat comforting:)
  13. Gerry8

    Gerry8 New Member

    Thanks Drewy
    My concern is that presumably when one finds the crunchy hose on the annual service the crunchy stuff has (or may have) already been circulating around the system for a period of time and may already have done some damage.

    I’d be so much happier if they had no possibility of going crunchy at all by not being there:(. If only I didn’t like all the other things the Viessmann 111W appears to do so well or if there was a credible alternative as good/similar design of combi with 46L storage in a neat package with modulation down to 1.8Kw with no rubber hoses
  14. Gerry8

    Gerry8 New Member

    Thanks for the parts price comment Millsy.

    You are correct, I do have great doubts and because I like the rest of the spec so much I’m trying to disabuse myself of those doubts and to see if am being fair in my assessment of Viessmann and the boiler. If there was another game in town that matched what I wanted that didn’t have these hose issues or didn’t have the price of spares issue or the doubts about Viessmann’ s attitude to applying the guarantee I would be off to play it.
  15. Rob Foster

    Rob Foster Top Contributor!!

    See if BG will take it on OR look at independant insurance this is usually cheaper..its covered for 1st year anyway...you are not obliged to take out further german insurance. Rob Foster
    aka centralheatking...Money saving expert have a whole section on this subject
Similar Threads - Viessmann 111W storage Forum Date
Expansion vessel change on a viessmann 200wv Gas Safe Registered Plumbers Only May 21, 2019
Viessmann Viterol 100 RF2 Central Heating Forum Apr 26, 2019