Viessmann Vitodens B1HE-199 suddenly started grinding loud and non-stop

erickyung

I've had it installed brand-new for almost a year now. It's been working fine without any issue and adequately providing plenty of heat and hot water for our family.

A few days ago, it suddenly started grinding really loud and the noise could be heard everywhere in the house even from the second floor. I ran down to the basement and realized it was from the boiler. DHW was on - I guess it was kicked on at the time. The whole box was vibrating and grinding non-stop. I quickly looked at the screen and shut of the service switch to cut off power to the entire system. I powered it back up and it's been ok for the last few days.

Usually when DHW kicks on, I can hear two quiet groans from the diverter value switching from heating to DHW. I believe these groans have gotten a bit louder than before.

Does anyone experience a similar situation with your Viessmann Vitodens boiler? It makes me worried quite a bit, especially it happens when I am not home. If it were to keep going like that for a long time, it probably could rip itself off the wall; if not, it would damage extensively. Do you think the diverter valve did not switch fully or flutter? Could it be dirty water or buildup?

My installer have moved far away. I need to find another Viessmann Pro in the area. Do you think another Pro would take on maintenance of an system that they did not install?

I hope this is just a fluke. This system cost me quite a bit and I hope it can work more than a few years before it shows signs of wear and tear.

Any help from the community is greatly appreciated!

GGross

Can you take some pictures of the system as it is piped?

what you are describing, especially if it didn't throw any error codes might be tricky to figure out. Off hand the diverting valve has 3 positions, heating, DHW, and center which is open to both, in my opinion if the valve were stuck in between a setting you could possibly get what you are experiencing, however the flow switch would have stopped the boiler from firing. It's possible there is or was a combustion issue, but between the mass flow air sensor and flame sensor something should have triggered a code. I would be more curious about piping and that valve, the boiler doesn't have a way to "prove" to itself the valve is in the correct position, it sends a signal to the valve and assumes the valve is able to correctly move. When you turn the boiler off and back on, the boiler signals the valve back to a preset position, which is what possibly fixed it.

erickyung

@GGross Thank you for your input!

I was expecting an error code too but looking at the app at the time, it did not indicate so and there was no notification afterwards.

I am wondering if I should call a pro to perform a boiler flush. But from looking at the setup, I believe there is a missing flush valve on the DWH supply side to isolate that loop from the rest of system.

66ej3rmql1pm.jpg

8asciulevwyn.jpg

yxolifpb37a6.jpg

GGross

Yeah it's nice looking piping but they really skimped out on valves. It might be a good idea to call a service company, have them drain some of the fluid and make sure it doesn't have a bunch of dark colored stuff in there, they would probably want to add some drain points as well. One thing I don't like to see is the fill valve left open, personally I want to know if there is a leak so it can be addressed. With all that ferrous metal in there if the system is taking on fresh water it will eat up that black pipe fairly quick, and put junk in your system. Water quality depending of course.

I don't particularly like the way that condensate drain is trapped outside the boiler either. People disagree with me on this one but every manual I have ever read says not to do that, at the very least it can be a spot to collect crud from the burner, which could clog the condensate and cause a bunch of nuisance issues. The condensate hose should run straight down to a drain or pump, not down and back up again

GGross

erickyung

@GGross Thank you for your valuable information again. Those pictures were taken after the installation almost a year ago. Shortly after the installation, I replaced the copper drain pipe with a shorter pvc drain pipe so that the condensate drain hose did not create a trap.

Interesting point about the fill valve staying open. I will contact a Viessmann Pro around my area and get an appointment for a full system flush and possibly install a flush valve on the DHW supply and a drain valve underneath the low loss header to drain out sediment.

erickyung

Well, the grinding noise just happened again and it happened on DHW call and there was no demand for heating at the time. Switching the system on and off seems to be the way to go for now until I get a Vi Pro here.

There are a dozen or so calls for DHW on a normal day. It just randomly occurs twice days apart and no error code is reported.

Next time I will do a 30s video and post it here. Possibly the video can help prove that something needs to be repaired/replaced and I hope the service call will be under warranty.

erickyung

@GGross I've found a service company in my area but their appointment is away out to spring or summer. If the incident keeps occurring more frequently, I will ask them to come and diagnose.

Both incidents happened around the same time of day. Here is what I am thinking:

Let's say I was running the kitchen sink faucet with warm water for more than half hour. At some point during that half hour the DHW temperature dropped below the setpoint so DHW call kicked in.

(Normally after DWH reaches 5 degrees above setpoint, it stops the burner but the pump is still on for a few more minutes. Then the diverter valve goes back to heating position.)

What if while the diverter valve was about to switch to heating, DHW call kicked in again. Would it switch or would stay? Or would it be confused and stuttered? Could that be the scenario I was experiencing?

GGross

In terms of control logic that would not cause a problem with the valve, from a control standpoint the valve can't really stutter. It can move to 1 of 3 positions, there is a delay between action in the control to prevent multiple conflicting actions happening at once. Now from a physical standpoint if there were some sort of blockage or the valve couldn't physically move to position the boiler would not know, and the next signal to move the valve may either not happen correctly or cause some sort of problem. I'm not 100% sure but I do imagine there is a possibility this is control related, I would think something physical though.

Jamie Hall

I don't find a recording of the noise, so I am quite unsure what is meant — but I will say this: in most cases of a grinding noise which continues for any length of time it is a bad bearing or gear train which is failing.

offdutytech

The installer didn't quite read the manual right. The spirovent is on the return pipe. and not either on the supply or low loss header. They have the air separator on the primary return to the boiler. There should be an air vent on the top of the low loss header where they look like they put a coin vent? Can you open what appears to be a coin vent to see if you can purge air from the system? It's possible there is air trapped in the boiler and when the diverting valve switches it makes the grinding sound. I've had a few after we installed the Vitodens that just needed more air purging and it went away.

They should have installed a few more isolation valves at the boiler for service. With a black iron header or any black pipe we always install a mag filter or low loss header with one. I agree i'm not crazy about the trap in the condensate tube. To rule that out let it drain into a 5 gallon bucket and let the boiler cycle.

Here is a screenshot from the install manual. The second pic is one we did a few years ago with indirect and actually had lots of room to work with.

IMG_1360.png

IMG_4373.jpeg

offdutytech

Also just for the heck of it is the boiler vented through the side wall of the house? If so see how far away the intake and exhaust are from each other.