Which boiler

digger18

Hi i am just wondering which boiler is the best vaillant or viessman

0e1

Both are good boilers with solid well built heat exchangers .Viessmann a bit more expensive and a bit harder to work on .

digger18

digger18 wrote: »

Hi i am just wondering which boiler is the best vaillant or viessman

As mentioned both are quality boilers.

ferryman35

0e1 wrote: »

Both are good boilers with solid well built heat exchangers .Viessmann a bit more expensive and a bit harder to work on .

Why would you say Viessmann is harder to work on?

Dtp1979

ferryman35 wrote: »

Why would you say Viessmann is harder to work on?

Different component layout.

lomb

Vallient had a lot of issues.Just look at youtube some corrected now. If run without water then a unresettable thermal link blows writing off the boiler/heat exchanger. Viessmann has a very nice heat exchanger but uses rubber pipes that could blow/clog.
Worcester is the best boiler spares are widely available and can be gotten cheaply. The primary heat exchanger doesn't clog easily as theres only one point of restriction at the top. Pcbs are reliable, ours has lasted 8 years. Fans last an average of 5 or 6 years, Gas valves are reliable.

Dtp1979

lomb wrote: »

Vallient had a lot of issues.Just look at youtube some corrected now. If run without water then a unresettable thermal link blows writing off the boiler/heat exchanger. Viessmann has a very nice heat exchanger but uses rubber pipes that could blow/clog.
Worcester is the best boiler spares are widely available and can be gotten cheaply. The primary heat exchanger doesn't clog easily as theres only one point of restriction at the top. Pcbs are reliable, ours has lasted 8 years. Fans last an average of 5 or 6 years, Gas valves are reliable.

Is this from your vast work experience or from your own boiler at home?

lomb

lomb wrote: »

Vallient had a lot of issues.Just look at youtube some corrected now. If run without water then a unresettable thermal link blows writing off the boiler/heat exchanger. Viessmann has a very nice heat exchanger but uses rubber pipes that could blow/clog.
Worcester is the best boiler spares are widely available and can be gotten cheaply. The primary heat exchanger doesn't clog easily as theres only one point of restriction at the top. Pcbs are reliable, ours has lasted 8 years. Fans last an average of 5 or 6 years, Gas valves are reliable.

A thermofuse is there for a perfectly good reason as running a boiler without water strangely enough can leave a boiler compromised which wouldn't be known until something unfortunate happened.

Vissmann don't have any heat exchanger issues? If there is enough sludge in a system to clog a Vissmann it will have a similar impact on any boiler over time and it's a installation issue not a product issue.

Don't kid yourself all manufacturers have issues, I know a WB service agent who won't fit them because they couldn't supply a part does that now mean all WB should be shunned? absolutely not that would be silly, all 3 of the manufacturers you mentioned make very good gas boilers.

Wearb

A plague on all their houses, I say.

lomb

Dtp1979 wrote: »

Is this from your vast work experience or from your own boiler at home?

Boiler at home and a bit of recent research. Worcester boilers are widely sold in the UK and most parts have the same part number between their boilers of different kw which means second hand and even new parts are cheap. I don't think you can say that about Vallient or Viessmann.
Rubber pipes in a boiler are bad, Vallient used to put them in but took them out and charge for copper upgrades obviously a cut back originally . Apparantly Viessmann still use them. Lots of good videos here
https://www.youtube.com/watch?v=jhS6992Dn6Q
https://www.youtube.com/watch?v=ryyKRxX1YTo
https://www.youtube.com/watch?v=J8oxpsJIG1M
https://www.youtube.com/watch?v=QC8KGBzWZw8

Im sure they are very good boilers Worcesters have faults too but long term spare costs/availability are important to me at least

Dtp1979

lomb wrote: »

One other thing I noted before I sign out of this thread is that Viallant boilers have the thinnest combustion seal which inevitably failed leading to internal fires if not changed regularly. They upgraded these to graphite but your man on Youtube reakons he still sees the newer seal failing at 5 years meaning that a service needs to be done every 4. I cracked open the heat exchanger in our Worcester a few weeks ago that I know for a fact that the last combustion seal was replaced around 2008 when the fan was changed so that's 8 years of use on a large 15 double rad system and the seal was old and thinned but totally solid and the narrowest part is around 5 times the width of the Viallant. Also with the vertical heat exchanger versus horizontal Im convinced that the oxides of combustion are washed down through the chamber as the combustion happens on top by the condensation keeping it very clean which largely it was. Proof was the condensate trap was full of ash and the heat exchanger and the lower sump of it had very little. Some reakon the Worcester boilers can run for 100000 hours without needing the heat exchanger serviced as they wash through as long as the flue gas analyser produces good readings.
Ps my boiler is in a shed so Carbon monoxide isn't an issue which is a killer.

if it's a hay shed with 4 open walls then yes you are correct.
You are the most dangerous type of diyer out there. A little knowledge can be a dangerous thing, especially seeing as you're opening up and working on gas boilers from tutorials on YouTube. Not to mention breaking the law

lomb

Dtp1979 wrote: »

if it's a hay shed with 4 open walls then yes you are correct.
You are the most dangerous type of diyer out there. A little knowledge can be a dangerous thing, especially seeing as you're opening up and working on gas boilers from tutorials on YouTube. Not to mention breaking the law

I find the engineering fascinating which is why I have an interest in them. I do have detailed knowledge and am not a Diyer .Signing out/

lomb

lomb wrote: »

I find the engineering fascinating as indeed the marketing smoke screen around them which is why I have an interest in them. I do have detailed knowledge and am not a Diyer .Signing out/

No your a youtuber not the best starting point, I don't use youtube neither does Dtp1979 not for boilers anyway;) I am glad your happy with your boiler but stop bashing other boilers you have no face time on as that's just silly.

Also you lost me at "The primary heat exchanger doesn't clog easily as there's only one point of restriction at the top" which is totally ignoring the negative impact contamination has on any boilers longevity even Worchester posh

DGOBS

cracked open the heat exchanger in our Worcester a few weeks ago that I know for a fact that the last combustion seal was replaced around 2008 when the fan was changed so that's 8 years of use on a large 15 double rad system and the seal was old and thinned but totally solid and the narrowest part is around 5 times the width of the Viallant

How fascinating, hmmm, do you realise OVERTIME you open a WB boiler heat exchanger they specify that you MUST replace the seal???
OPPPSSSS.

DGOBS

DGOBS wrote: »

How fascinating, hmmm, do you realise OVERTIME you open a WB boiler heat exchanger they specify that you MUST replace the seal???
OPPPSSSS.

ER.... that's not what it says on fooltube, twitter says your well wrong too and I don't even want to tell you what Facebooks been saying:eek:

RJF

I presume DGOBS means "EVERYTIME".

RJF

RJF wrote: »

I presume DGOBS means "EVERYTIME".

He's dyslexic;)

RJF

Do you mean diylexic?

RJF

RJF wrote: »

Do you mean diylexic?

Yea, that thing when you get grumpy after 3 glasses of vino

bewhiched

digger18 wrote: »

Hi i am just wondering which boiler is the best vaillant or viessman

I've a vissemann and find it brilliant none trouble with it at all nice and quiet water heats quick too brilliant