Vidodens 200-W Three way Valve Heating/ IDHW Testing pulling out diverter motor.

heathead

I have a B2HE-120 That is used at a vacation home. Two weeks ago tried to use the viessmann app to turn on DHW. It heated up the boiler but didn't heat the DHW. Then Truned it off and retried and it worked. Then off for two weeks. The boiler had lost power ie whole house did also. Today turn on hot water on boiler control panel and the 3-way valve stuck on heating no hot water running through Coil in IDWH only going to low loss header. Go into service menu and try and switch between heat only and DHW and Mix. Didn't work Heat only, not switching to DHW Indirect. After multiple times on and off main switch and then trying to excersise vlave it worked.

Can i remove the motor and watch for movment, or is it directly hooked to water side.

Two possible chocies the valve is to hard for the motor to turn or motor is bad. I believe the motor is a stepper motor so it reset when the power goes out.

Any known problems?? Which part should i be looking at. Thanks

mattmia2

don't know if that actuator can be removed without opening the water side but most valves are set up so that the actuator can be removed while keeping the water side sealed. The actuator could be sticking, it could have dried up grease in it that has turned more cement like. More likely the valve itself is getting mineral deposits on it while it sits unused. Possibly exercising it may times with the actuator removed could free it up more permanently. Adding some treatment to the system water is more likely to help.

Alan (California Radiant) Forbes

Here is a video on the B1HE diverter valve.

https://www.youtube.com/watch?v=_L_0Xensix8

mattmia2

that looks just as sketchy as the cooling system on my 325i. something else that shouldn't be made entirely of plastic

heathead

Alan,

Thank you. The motor is working. and the video is showing that it pulls the valve out in DHW mode. Will go back and try and hook the end, I didn't see how it hooks but it must. I thought it was like a radiant manifold that just pushed the pin down to activate heating mode. Although it appears to function that way, In the video it shows it hooking in and pulling the rod out which makes much more sense, not just relying on the pressure to push the vavle in DHW, the motor pulls it out. Thanks Again

heathead

Just so everyone knows the motor must hook on to pull out the valve. It will seam to work without doing that, but it needs to hook to pull the valve out. Most times it will work without hooking the end, but that will just fail again. Either it broke loose when it reset the stepper motor or was not assemblied correctly from the factory. Time will tell. Huge thank you Alan

GGross

If it works sometimes and not others my first guess would be that there is something physically blocking the valve (air, "junk" etc) if it has never worked right I would suspect there could be a misplaced check valve. the valve will reset itself on power cycle, can you take a pic of how the boiler is piped? I have seen similar motor/valve setups that had a restriction in the valve body cause the motor to pop off

heathead

The expansion tank ties in the back between the low loss header and the dirt seperator.