Viessmann boiler failure

[Doodlebug]

I've had my old central heating Baxi boiler for over 25 years.
It has never ever broken down in any way and is keeping me warm this morning. :-)

[ppppenguin]

Old cast iron boilers seem to go on for ever. They're not fussy about a bit of sludge and limescale and there's very little to go wrong. They also use a lot more gas than a modern condensing boiler.

[Raditechman]

Like Doodlebug I  have a 20+ year old gas boiler, which serves me well. I never had a service contract on it until 3 years ago and now each year it gets a service, which is mainly checking the combustion is OK.
Only faults I have ever had have not been with the boiler,  the circulating pump once and also the change over valve, both of which are in the airing cupboard and were replaced by me.
They always try to get me to buy a new boiler but having seen several people with modern boiler breakdowns I hang on. 
I remember Jeremy getting his new boiler as he wrote about it on another Forum.
I still have an immersion heater as a back up, and plenty of thermostatically controlled electric convector heaters. Including an old Belling where I have a thermostatic plug adapter.
When my gas boiler eventually gives up I may just go all electric as I think that modern gas boilers are too prone to breakdowns.

John

[ppppenguin]

I remember Jeremy getting his new boiler as he wrote about it on another Forum.

I (Jeffrey) got a new boiler about 5 years ago. I don't recall Jeremy (aka Pamphonica) getting one and writing about it.

Since I did the installation myself I reckon the new boiler paid for itself in under 4 years due to reduced gas usage. Install cost a little over £1000. Unless it's a distress purchase (old bolier gone badly wrong) then the economics are less good.

If a decent boiler is installed properly (obviously I didn't clean my system well enough) then it's still the cheapest form of heating if you have mains gas. Best makes are Worcester-Bosch, Viessmann and possibly Vaillant. Avoid most of the others.

Actually the best form of heating is to upgrade the insulation on your house so you don't really need central heating. This is neither simple nor cheap but the idea of effectively zero heating bills is very attractive. Passivhaus is mainly applicable to new build but there is a related scheme for retrofit. Only worth doing if you are doing a very major refit on your house. https://en.wikipedia.org/wiki/Passive_house

[Doodlebug]

Not only is my old Baxi still going but the same pump is still running after 25 years!
Never had to drain any radiator either so no boiler sludge build up over the years.

I installed it all myself and as you all know the best bloke to do reliable work in one's
own home is YOU!

Some years ago I spent over £200 on boiler spares just in case, but touch wood, never had
to use them.

[Raditechman]

Yes, I meant Jeffery not Jeremy, for the new boiler. Time to clean my specs!

John

[ppppenguin]

Never had to drain any radiator either so no boiler sludge build up over the years.

Not necessarily. There's only 1 dose of limescale in the water but black sludge is a reaction between water and iron in the absence of air. It goes on continuously unless there's enough inhibitor in the water. I don't know how long inhibitor lasts before it loses its effect. If the system is vented (with header tank) as against pressurised there's also a certain amount of air and muck getting in that way. It's a prety small effect.

[ed731pdh]

From personal experience, flexible couplings are the spawn of the devil, and no matter how well you keep the system clean, the hot coupler will always erode from the inside out at a bend in the coupler.  Plumbers (and I use the term lightly) tend to use them for connecting up the water under sinks and baths, rather than do a professional job and use brass fittings. Lazy lazy lazy, as a friend found out to his cost when the hot blew under an upstairs sink just after he went out, and came back 20 minutes later to a house full of steam, the boiler running it's nuts off and the kitchen ceiling on the floor.

As to boilers, we are on oil as we're in the sticks, and the house boiler is a Grant Combi 90 mk2.  I recently had to carry out some work on the unit as the always weepy 15mm nut on the top of the heat exchanger had run out of torque and it needed a new unit. You can imagine my surprise when taking the old unit out to find the previous house owner had gotten a supposed boiler engineer in and had used instant gasket rather than the proper fibre washer.  Add to this a new pair of thermostats as the old ones were getting unreliable and a days worth of work ended up with me on my knees tuning the system with a thermocouple.

If you want something done right, as I found out, if you can do it, do it yourself.

[ppppenguin]

The stuff is like car radiator hose. I suppose that fails too, in the same way.

Perhaps replace every 4 years on spec, to save a flood.

[ed731pdh]

I never was the fan of flexible hoses in mission critical applications.