Viessman WB2B With Power pump module not powering circulator

SeanSylva

HI folks, I'm new to the site and, full discloser, a homeowner not a professional. I have a Viessmann WB2B 26 boiler with the power pump module and I use taco switching relay boxes to switch on my three grunfoss circulators-one for indirect how water and two more for two zones. The fourth circ is controlled by the boiler for the low loss header. The two heat zones are working fine but I don't have hot water. The system appears to be calling for hot water since since the red Zone 1 led on the Taco switching relay box is lit up. However there isn't any power going to the circulator pump coming out of slot 21 on the power pump module. I'm thinking it may be a relay?

I'd appreciate any advice.

PerryHolzman

Lets start with the basics:

1) Do you know who installed it - and are they currently working with Viessmann Vitoden Boilers? Truth to tell: If you have a local contractor who is familiar with this boiler - they will fix it faster than you will (and are likely worth the cost).

Who is doing the annual service (and I assure you that you really need someone cleaning the heat exchanger with the cleaning spatula tool every year if you don't want your hear exchanger to plug up and require replacement).

If you do not have such a local heating contractor who is familiar with these boilers... It can be a real crap shot. Politely ask if they would be interested in learning about your boiler and working with you. Note that most of the heating contractors in my area have a fairly simple rule when it comes to mod/con boilers. If they did not install it - and are not familiar with it or don't know where the parts are stocked - they want to immediately replace it with whatever their current boiler is, instead of becoming involved in a multi-day troubleshooting and getting parts saga... as few homeowners will pay for that.

2) If you are somewhat computer savvy: Go to the Viessmann USA Site, find the page for "manuals" , then select the "historic product manuals", then select wall mounted gas boilers, and finally select Vitodens 200 WB2B (on the right).

Download the Start-up/Service Instructions manual for your size boiler, and any other manuals that you are interested in (I have the full set for my WB2A boiler).

Study the service manual - and learn how to access the troubleshooting Diagnostic Codes (In my WB2A manual this section is titled "Troubleshooting Steps").

Follow the instructions and see if there are any fault codes.

If the issue is boiler related - there will almost certainly be a fault code. Then follow the manual on what the identified issue is. Sometimes after fixing 1 issue, there will be another fault code for another issue (it happens).

Do not otherwise mess with the boiler coding. However, for certain part changes (such as the main control board) you do have to record the old settings in about a half dozen places; and then program those back in after you have installed the new control board (at least I had to do that on my W2BA).

3) Now... are you enough of a technician to fix the boiler or not. If you are not comfortable I hope that in your local heating contractor search that you identified the one you most trust... as you will need to call them in, provide all the manuals to them, tell them what the fault code is (they will want to verify) and let them take it from there.

It would likely be useful if you also have handy on your computer the appropriate youtube videos on how to open up, access, take-apart, etc videos for your exact boiler. It will save a lot of time.

If you feel you can tackle this yourself... Download the Viessmann parts manual, and order the identified parts. Boston Heating Supply is a Viessmann authorized dealer who sells parts to homeowners - at least outside of Massachusetts (I'm not sure if they can sell to homeowners inside their state - or just heating contractors). They typically take a few days to get to you. Contractors may have access to at least some parts closer and quicker. In my case, for contractors some parts are stocked 100 miles away.

If you are going to do your own You may benefit from buying the appropriate Viessmann tool kit for your boiler, and the cleaning spatula tool for the heat exchanger.

Note: When my WB2A boiler was installed the regional Viessmann rep trained me to take the boiler apart and reassemble and access the main control card as part of the deal. I've spent much of my life repairing an rebuilding controls and mechanical things - so the boiler fitted within my existing mechanical, electrical, and controls skill set; and I wanted to know how if I needed to. Turns out the heating contractor who installed it never installed another Viessmann boiler and I have a unique boiler in the area.

I wish you well with this,

Perry

PerryHolzman

I apologize that I left something out that is important:

Please understand that many contractors are willing to work with cooperative and helpful homeowners, but not ones that interfere. Also, that they have to make a reasonable profit to pay for the expense of their shop, vans, and normal stock, and insurances.

If you do not already have a contractor familiar with this boiler, or can find one that is - then I believe that most contractors would not mind if you ask them to assist you if you tell them that you have the manuals downloaded and printed, have youtube videos on how to access things and take things apart, and even if you tell them that you have a fault code and an initial diagnosis (you could also have the tool kit and the special cleaning tool). That you just want them to take over from there, and understand that their billing time includes the time it takes them to look at the manuals and watch the youtube videos.

Please note that if you do not have this information in advance that it might take them 3-5 hours or more for them to get it themselves - and contractors billing hour rate in many areas are a 3 digit number with the 1st digit usually less than 3 (and it may vary depending on the situation and attitude of the homeowner). Its not unusual for a contractor to spend 8-12 man-hours acquiring manuals, finding videos on how to access things, troubleshooting, talking to the Mfr technical service, and locating parts for a modern mod-con boiler they know nothing about - and then additional hours to get parts (3.5 hr minimum round trip in my case: that's why they rather just replace them with something they are used to working with and parts at this time are relatively local).

Many contractors will insist on them supplying the actual parts (and they may tell you stories on why "my insurance will not allow me to install parts that I do not supply" which I have heard - and a clear lie at least in my state due to state laws/regulations that were implemented some years ago).

Note, that if you do find a contractor that will install parts that you have on hand... they will not warranty their work for that. New parts that fail does occur... and you are personally responsible for seeking any warranty replacement from wherever you got the parts. Note that part warranties are from time of purchase. So even if you purchased from an Authorized Viessmann Supplier (such as Boston Heating) - the parts warranty likely expired while it was sitting on our shelf unless you just purchased it. Boston Heating (and others) will likely require appropriate documentation from Viessmann (case code, etc.) before they will warranty replace it. I had a bad new main control board for my WB2A boiler which I had just purchased (thankfully in that case due to its cost - pricey) - and I had to cover the cost of shipping it back to Boston Heating after working with Viessmann Technical Service for most of a day and getting their replacement authorization code. It took about a week for me to get the replacement new board in. Fortunately this was in the spring and the house would not freeze - but it was rather chilly (and no hot water).

If a contractor installs a bad new part they supply - then its under their warranty, and they can likely have a replacement part in a day or two (and perhaps the same day).

That is why I recommended above that its best if you have a local contractor familiar with the boiler, or at least work with you if you have the technical information ready for them.

Deciding to go it alone... has cost savings but has other risks as well. It's your choice. I figured that I should mention this too you.

Perry