when i run the hot water tap on my viessmann vitodens 100 boiler it goes hot cold hot cold i have changed the ignition tranformer but its still doing it you can hear it ignite then go off then on again any suggestions
viessmann vitodens 100
- Thread starter raisens
- Start date
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when the tap is running the temp went to 99 it read comfort underneath then the reset button started flashing and f2 came up on the lcd
M
mysteryman
Check if it is leaking heat into the central heating outputs. If not, it needs a thorough powerflush.
If it is a WB1A boiler, turn both the knobs fully anticlockwise and then turn the power off. This stops the diverter valve in mid position. Turn the red flow isolation valve handle round so the handle points forward. The black drain off in front of it is then connected to the boiler, which is isolated from the heating flow pipe. You can then powerflush the boiler between the two black drainoffs, this one and the one on the right.
You should also powerflush the entire heating system, opening the radiators up one by one so that each rad has been flushed. This is better done first.
You will then need to refill and vent according to the Service instructions.
If it is a WB1A boiler, turn both the knobs fully anticlockwise and then turn the power off. This stops the diverter valve in mid position. Turn the red flow isolation valve handle round so the handle points forward. The black drain off in front of it is then connected to the boiler, which is isolated from the heating flow pipe. You can then powerflush the boiler between the two black drainoffs, this one and the one on the right.
You should also powerflush the entire heating system, opening the radiators up one by one so that each rad has been flushed. This is better done first.
You will then need to refill and vent according to the Service instructions.
I would expect its more likely to be just the plate HE which is rather blocked.
Of course apart from cleaning/replacing that any remaining dirt in the systen needs to be cleaned to stop it happening again.
Its not the manufacturer's dirt so that problem will not be covered free under the warrantee.
Tony
Of course apart from cleaning/replacing that any remaining dirt in the systen needs to be cleaned to stop it happening again.
Its not the manufacturer's dirt so that problem will not be covered free under the warrantee.
Tony
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M
mysteryman
The whole system needs cleaning. There is no reason to fit a new plate heat exchanger. There's nothing wrong with it - it's just partially blocked, like the rest of the system.
I normally just clean them but always remove them for that. Power flushing the boiler rarely cleans them very well.
In any case its quicker to just remove the plate.
Depending on how bad the system is in many cases it will do quite a good just flushing through with mains, ideally each rad at a time.
Tony
In any case its quicker to just remove the plate.
Depending on how bad the system is in many cases it will do quite a good just flushing through with mains, ideally each rad at a time.
Tony
Sorry to hijack this thread but I have a problem that mysteryman half answered above and wondered if you guys could help?
With the hot water running the boiler fires up normally and heats the water as expected. Recently it has now also started leaking hot water into the ch system despite this being selected to off on the control panel.
Any ideas on what may be wrong?
We have recently had a Viesmann engineer out to give the boiler a complete overhaul following a long run of F4 F5 problems. Thankfully these problems have been resolved (the boiler is just over 3 yrs old)
Any advice much appreciated.
Yaks
With the hot water running the boiler fires up normally and heats the water as expected. Recently it has now also started leaking hot water into the ch system despite this being selected to off on the control panel.
Any ideas on what may be wrong?
We have recently had a Viesmann engineer out to give the boiler a complete overhaul following a long run of F4 F5 problems. Thankfully these problems have been resolved (the boiler is just over 3 yrs old)
Any advice much appreciated.
Yaks
M
mysteryman
If it is leaking heat into the central heating during a hot water draw off, then your diverter valve is sticking. These problems are all caused by a system which is dirty, and therefore needs a powerflush. Just changing the plate heat exchanger is a waste of time and money.
Everything mystery hass said is spot on
I would do as agile says take the plate off & give it a clean !
Every fault that occurs with a boiler ? can be cured by power flushing ?
Every fault that occurs with a boiler is due to , the system is dirty , or it was not flushed correctly , or the wrong inhibitor was used , or not enough inhibitor was used ect ect ect
Every fault that occurs with a boiler ? can be cured by power flushing ?
Every fault that occurs with a boiler is due to , the system is dirty , or it was not flushed correctly , or the wrong inhibitor was used , or not enough inhibitor was used ect ect ect
M
mysteryman
These things are not matters of opinion - they are matters of fact. If the primary side of the plate heat exchanger is sludged, the rest of the boiler is sludged as well. It all needs a clean - or powerflush.
M
mysteryman
It is perfectly obvious that the problem here is on the primary side of the boiler.
The diverter valve is letting by, probably due to dirt in the system making it stick.
The diverter valve is letting by, probably due to dirt in the system making it stick.
Well the way I see it he can clean boths side's of the plate out ! when it is removed !
The old boiler manus are having a field day on this , boiler fault nothing to do with us carp in the system , remove a part its got a stain on it =carp in the system ect ect
The old boiler manus are having a field day on this , boiler fault nothing to do with us carp in the system , remove a part its got a stain on it =carp in the system ect ect
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