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.

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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.

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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.

erickyung

@GGross @Jamie Hall @offdutytech I finally got a video of it:

https://youtube.com/shorts/BDicnQngXSQ?si=sQZ7az4RlDc8MdEY

It started about a week ago after almost a year of working fine. It happens once every few days. When it happens, it's on DHW call.

I switch off the entire system each time to reset it. When it starts up, it groans and clicks once quite loud.

I have addressed the drain hose issue.

offdutytech

@erickyung if you download the IOM from the Viessman site it has a test mode to move the diverter valve to see if that is working. In that video it's hard to tell if the burner was firing or I just haven't had enough coffee this am. If the burner wasn't on the issue is on the boiler/ water side of things. I'm still curious on what the venting outside looks like

GGross

You can just barely make out at the bottom of the screen burner modulation 27% so there must be flow enough to make the flow switch, but the bouncing pressure gauge sort of implies the pump is dead-heading against something (partially blocked valve?). From the home screen if you press the button that looks like 3 lines stacked vertically (menu) scroll all the way down to "Settings" from settings scroll down to "Service" from service select "Actuator Test" A prompt will appear telling you the test will turn everything off (stops call for heat etc) in the actuator test there is an option for the 3 way valve position, select that and cycle the valve through all positions, listen for any noises, if you don't get any noises try turning the pump speed up and moving the valve position, or try each valve position with the pump speed up, probably don't need the pump to 100% I'd start at about 50% or so

For the sake of consistency you may want to close the fill valve during this operation, I am of the opinion that the fill valve should be closed unless you actively lose water pressure, which means there is a leak somewhere that needs to be addressed. I doubt it has much to do with this, but it might be a good idea to eliminate it for the test

erickyung

@offdutytech

At about 24s mark in the video, I turned on the screen, the modulation was at 26% for DHW so the burner was on.

The vent is about 3' - 4' from the boiler on the other side of the wall.

offdutytech

On the B1KE there is an inlet filter sieve as well. Not sure of the water quality you have but with the issues you are having I would want to look at it. I'd agree trying the heating side pump speeds to see if it has any change. What we see and hear is this only on a DHW call only or Heating Call? Does it happen at only low or marginal fire of the burner?

As for the venting is that in an inside corner of the hose where two walls meet? I'm not a big fan of that vent termination, it has a tendency to recycle flue gasses which cause issues long term. We usually two pipe the vent like they did, but like to provide more separation between intake and exhaust gases.

In this situation if I was servicing this I would check the water side of things. Both DHW and Heating. In addition I would also pull the burner and check the heat exchanger for good measure if we could not determine any issues on the water side. I can say that I have not seen this issue on any Viessman that I have installed or serviced.

erickyung

@offdutytech

Mine is B1HE. The water quality here is quite good - I don't see nasty buildup around faucets, fixtures and shower floor. So far it has happened 3 times on DHW only, a few days apart. I am not sure if timing is relevant here but they were all around ~9pm. The one time I took time to record, as it was happening, the modulation was around ~20%.

The two vent/intake pipes go straight out the wall where the boiler is hanged, one 90 elbow from the top of the boiler and straight out about 4'. The room above cantilevers 4' from the basement wall.

Thank you for your input! I will try to get a Vi Pro in my area to look at it. At this time in the Northeast, most plumbers are busy with new installations. Maintenance gets pushed to late spring or summer.

Jamie Hall

Thank you for the noise! That's a valve or damper trying to move — and failing.

More important, you left out a critical detail: at the top of the boiler there is a small pressure gauge on the pressure relief valve. It is bouncing exactly in time with the noise.

So it's a valve in the boiler circulating water. I'd not care to say which one without being there — though a diverter valve is a likely candidate.

GGross

Agree that noise is the valve or something at least partially blocking the valve. The venting is not my preferred method as it could allow flue gas recirculation, but it will not cause the problem you are currently having and is approved by the manufacturer. After solving the valve mystery I would be making extra sure the flue gas is not being sucked back in to the intake, this is a common issue with condensing boiler installs and even if it does not cause immediate damage every time it greatly reduces the life of all internal components at a minimum. This valve issue is the most important thing in my opinion, the pressure gauge bouncing implies the pump is on/off dead heading against something, best case scenario it will lower the lifespan of the pump, more than likely that blockage is also cutting off the expansion tank to the boilers heat exchanger so this is very bad indeed.

Service techs don't seem to like pulling these apart but they are not terribly difficult to deal with once drained. Lots of clips and o-rings holding things in place I would put a couple towels in there before tearing it down. I imagine someone pulls the valve out and can tell whats going on pretty quickly. Parts should have a 5 year warranty from date of install, perhaps the installer can come do this for you since it is so recent since this started?

There is a main programming control in the back of the control box on the bottom of the boiler, fitted to the top of the box is it in (helps avoid moisture) the part the contractor sees and wires to in the front, easily accessible both in a sealed gasketed box, and there is a board on the left side of the cabinet about halfway up that controls the burner. The control on the front is able to be completely removed in about 5 seconds, giving you tons of room inside to work. just need to keep water away from those, especially the wire as the water can run down them into a control. Actually it would be best imo to remove the burner assembly entirely before tearing it down just to make sure everything looks OK in the heat exchanger, that would keep the gas valve/ fan away from the water.

erickyung

As a home owner, there is not much I can do at this point but it does worry me. Whatever the problem is, it is failing but not completely.

I will send the video to the contractor and see how quick he can come and service it. Do you think without an error code, Viessmann would process this issue under warranty? Does Viessmann cover labor for a contractor to perform the replacement?

Thank you all again!

GGross

If the valve needs replacing they would be able to warranty it for sure, my suspicion is that cause of this is not the valve itself, the valve is being affected by something in the fluid or piping. A good contractor that sold this job would come out and take care of the labor within the first year, looks to be a very expensive install and whoever did it took care to make things pretty nice (minus the lack of drain valves of course). Viessmann is almost definitely not going to pay for labor, and to be honest I'm not convinced this is a failure of their device due to defect, but like I said they will definitely cover the part.

erickyung

I just recorded another longer video of a DHW call, at the tail end right before the burner turned off. Apart from the humming noise of the pump, I can hear the water circulating, like water running. I am wondering if that is normal. Should it be more quiet? Or could it be air that causes noise?

Skip to 3:15 mark, the sound of the diverter valve moved back to heating position. That long groan does not sound good to me. Do you agree?

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

GGross

"I can hear the water circulating, like water running."

That is usually air in the system. I'll have to listen to this later with headphones as I cant make it out with my little speaker

erickyung

I called up the original installer and he came today to find that the system water pressure was a bit low. He adjusted the valve to let more water in. It was at borderline between white and green. Now it's at 20 psi.

He ran a DHW call cycle. This time I didn't hear the water running sound anymore.

I will continue to monitor DHW calls. If it happens again, he'll come and flush the entire system. So for now, it's not too bad.