On Thursday, 9 April 2020 16:04:02 UTC+1, Dave Plowman (News) wrote:
In article ,
John wrote:
On Thursday, 9 April 2020 13:34:19 UTC+1, Dave Plowman (News) wrote:
In article ,
Brian Reay wrote:
We've had one major issue- fixed either under warranty or the service
contract, I'm not sure which, there was another minor problem but I
think that was related to the other one. At the last regular check up,
the engineer who we see almost every year and have got to know a bit,
commented it was as good as new. Certainly it seems to work well enough.

Seem odd to pay a great deal of money to be told everything is OK once a
year? ;-)

Navien heat exchangers do not need cleaning. All self cleaning boilers
need is flue gas sensors to determine of the burner is out. If so it is
flagged on the display, or if so bad it locks out.

Quite. What I liked about the Viessmann.

EVs do not need servicing. But the rolling parts do need a walk around.
The MOT does that.

My one fault was a split rubber hose, which took out the gas valve. Oddly,
the original drawing of the boiler in the manual doesn't show this rubber
hose. Copper pipe all the way. May have been added to further improve NVH..
It looked to be a silicon rubber one - so may have been unlucky it split.
That type seems to last forever in a car.

They have a kit to change the rubber to copper pipes. Get it. The rubber disintegrates causing problems like impellers on pumps disintegrating. The idea of the rubber water tubes was to move them out of the way for accessing components behind when repairing. Some makers, Ideal, Baxi, Viessemann have plastic hydroblocks. These cause water leaks after a while where pipes join because of the shocks of mains water. The makers say they are fine. Responsible installers knowing the problems install small shock arrestors on the cold water main just before the combi. This prevents/reduces the problem.. Viessmann now have a shock arrestor inside the combi. At least Viessmann has recognised and addressed the problem.

The likes of Intergas only use metal where water is.