Viessmann 100 F2 Help!!

[roger456]

Hey guys,

I have a Viessmann Vitodens 100 model WB1A24. Have had it for about a year now and always had F2 and very few F4 alarms. Now I can't get the unit to work at all....

My situation is that I start it up, goes to the cut off temp of 210 to 220F on the initial startup which is fine. Then drops below 160F and starts the second cycle. On that send cycle it cuts off at 220 to 225F which again is fine. The part I don't understand is that for some unexplained reason it restarts a second or so after cutting off at the 220F mark and goes to 245F or so and then F2 alarm. What would cause it to restart as it is already at temp?

Today I replaced the boiler temp sensor thinking it was flaky but that was not the case. It did not help at all. Still the same situation

Can anyone help....my family is without heat and hot water.

 

[Agile]

I might also have suggested the temperature sensor could be intermittently faulty. But I would have asked you to monitor its performance before rushing to change it.

But the operating temperature seems far too high to me. What happens when you turn the temperature control knob down? What position have you been using it in?

Tony

 

[roger456]

I turned down the temp knob and did not make a difference. It would still go over the temp after completing the second cycle. I have it at 12:00 right now but have tried it at many different positions with no change to the problem

I have a hot water storage tank on it too. I just turned the temp controller on the tank down so the system thinks the tank is to temp and now it is trying to heat up the house. Has ran for 5 minutes now and max out at 190F so I am guessing it uses a different temp ramping rate once the hot water system is to temp? - Does that make any sense? - Now the knob is at 2 o'clock position (optimal position I believe)

Not sure if I should let the house warm up or put the temp on the tank back up to see if will work fine??

Are there different ramps for different modes? And what temp should the hot water tank temp be set to?

 

[roger456]

I have it going from 100 to 180 when I have the heating system triggered but as soon as I turn the temp sensor on the hot water tank to a higher setting to heat up the hot water for the house, it does the same thing. It goes past 245F after the second cycle. I turn the temp knob on the front to 9 o'clock and still does not do anything. Is it locked up in some type of mode? Can I reset the set point on this unit to be a lower range? If so, how?

Pls help me out if you know something about this unit....

My house is still not heated up. roughly 2200 sq ft. Anyone knows how long it should take to heat up? Should I turn the dial up so that it might work faster....just don't want it to trip....thoughts??

 

[JohnD]

call Viessmann Service on 01952 675060 and they can send someone out to mend the boiler at a fixed price of £190 if you are outside the M25.

roger456
Joined: 16 Oct 2010
Posts: 4
Location: British Columbia,
Canada

I'm pretty sure he is outside the M25

They might charge more than £190 to cover travel time.

Odd, because I thought the Vitodens 100 was built specially for the UK market. Mine has no black knobs on it.

 

[mysteryman]

You are so right.

The boiler may be a different model in Canada. He should call Viessmann in Canada.

 

[Agile]

For a start his boiler gives the temps in fahrenheit which is a clue to me that its either slightly different or set up differently.

For someone who says they dont work for Viess thats just as well because sending a staff engineer to Canada to do a £190 fixed price repair might be a sackable offence!

Those instructions are in relation to power flushing the boiler and system. I would be surprised if Viessmann really expect all their boiler owners to have power flushing pumps kept in the under stairs cupboard.

My advice if we decide that its sludged up is to get a heating engineer to do the power flushing for you. Bleeding a little water to see what colour it is might give a clue.

As have probably realised we are based in the UK.

Your Canadian Viessmann contacts are:-

750 McMurray Road
Waterloo, ON N2V 2G5
Canada

Tel. (519) 885-6300
Tel. (800) 387-7373 (Toll-Free)
Fax (519) 885-0887


Tony

 

[mysteryman]

My name and where I work are part of the mystery.

 

[roger456]

Guys,

I just had a power flush done a few months back. The water is a little dirty as I noticed when I swapped the boiler temp sensor but very minor.

I just need to know why the temp goes so high when the system is setup to heat the water and the front know does not control the range that the water temp goes to. Is it controlled by the temp sensor on the hot water tank and that causes the boiler to keep ramping the temp up? Pls explain....

When I set the temp to 80F it still does not trip out. If I put it past that it does. Any insight that you can share would be appreciated even though we are many miles apart.

Thanks in advance,
Roger.

 

[mysteryman]

If the water is still dirty, that can be the problem. Your diverter valve may be sticking. Please give us the serial number.

Many boilers can display temperature in Celsius or Fahrenheit.

 

[roger456]

The serial number for the viessmann unit is 724422703262. Can I just clean the diverter valve to atleast get the hot water running for the weekend?

Thanks again for the help!!

 

[mysteryman]

It is worth a try. Dirty system water is never good news.

 

[roger456]

Sorry, what is the process to clean the diverter valve?

 

[mysteryman]

If the boiler is the same as the UK market one, you remove the two screws in the horizontal plane, one each side of the diverter motor, and lever the valve out.

 

[roger456]

Can you attach a picture of the diverting valve for me? Even if mine is different I should be able to figure it out from a picture. I just need to get this running. Two nights now and its pretty cold for my family.

Let me know.
Thx.