Vitodens 200 problem

Dave Yates (GrandPAH)_8

I had a similar problem with my Vitodens. Sometimes it would barely run, turning off and on frequently, and emitting enough uncombusted gas that I could smell it. The problem was due to metallic dust clogging the mesh at the modulating valve intake. I cleaned the mesh and vented the pipe for 10 or 20 seconds (make sure you have good ventilation when you do that) and the problem hasn't come back in over 1 year. You have to remove the cover to access that valve, but it's easy to find---it's the first box on the gas line. Hope this helps.

Jay_41

Vitodens 200 problem

I have an Vitodens 200 combi boiler no tank.
Having a on and off problem of no or little DHW.
Changed flow switch and DHW temp. sensor.

Any help would be great.

Thanks Jay

Derheatmeister

How about the solenoid valve maybe its hung up?.Also you know that this setup does not supply endless hot water ?

Derheatmeister

Define, little hot water. one shower? Two at the same time ?

Jay_41

Vitodens 200 problem

when it works it works great no problem, however sometimes it just gives 80-95 degree water

Derheatmeister

Does it make a difference if it is summer or winter,One Shower, Two showers or one shower and the washer going or the dishwasher at the same time?

Jay_41

Vitodens 200 problem

summer or winter is the same, I have 4 of these units and the others don't seem to have a problem. It serves a one bedroom one bath no washer apt.

When it works there is tons of hot water, the problem has no patten such as outside temp or time of year.
Jay

Paul Pollets

Timer

Have you checked the timer function?

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Derheatmeister

Did you check the "Diverter Valve Or also solenoid .Maybe it's hung up I'm not sure have not worked on a combi in a while ! or maybe some debris are in there ?

Simply Rad_2

Combi

I recently installed a combi boiler for our own home. I think I understand your situation. We are now in the mid winter heating mode and my system heating curve is set at 1 with a max temp of 140. Lately its been averaging around 135 degrees. When the boiler is running that hot it over heats the DHW exchanger. When you first open the faucet its very hot around 130 degrees. Then the boiler recognizes this and immediately modulates down or even shuts off. Then the domestic hot water cools even down to 85-90 degrees. The boiler see this and starts back up and but it takes time to get up to temp eventually it achieves the set point and idels. I find that this cycle takes about 2 minutes to come to a steady temp. Are you using the DHW comfort function switch on the Comfortrol? This gives you hot water faster, but still has the temp swing. I actually am making a call to Viessmann to chat about this.

Jay_41

Can you let me know what Viessimann says about your problem,it sounds a little like what is happening to me.

Thanks

[Deleted User]

vito-combi question

Hello. When was the last time the water filter was serviced? Just a thought.

simply rad_3

Combi boiler

Jay
I spoke with Viessmann and they said a few things. If you are using the DHW comfort switch, then set your DWH temp to 122. The switch keeps the internal exchanger @122 degrees so they will match. Instead of replacing the flow switch next time clean it. I am trying this on my unit as we speak. Otherwise do not use the switch and set the DHW to what ever you need.
Our experiment seemed to work. Try that and post the result

Jeffrey

Jay_42

Vitodens 200 problem

I hope that is the problem I will need to run a pipe somewhere to test, the owners had a temp. electric hot water heater installed because the Tenants were yelling so loud.

Jay