Bosch Combi Boiler ZBR 28-3 Issue

oki2oki

Hi,

I am having issue with my Bosch ZBR 28-3 boiler. When enclosure is closed boiler works and operates fine for day or 2. And then i get ER code on it. Seems to be working fine when i take of the enclosure and let it run without it. So seems like something is wrong with combustion. I check everything and cleaned everything that i could and what was suggested in the manual but i am still experiencing this issue.
What i noticed is that my silencer, gray thing in back of the boiler, is not really properly sitting or connecting on the bottom. Please see my picture. There is a gap there and i see some grease there as well (where i highlighted). But i am not sure if this gap should be there.
Should i get new silencer and installed it? Or should i take this one apart and reinstalled it and make sure there is no gap there? Its just weird that it works fine for day or 2 and then this happens and i need to take the cover completely off. Most of the time it happens during the night when we are sleeping. During the day it always works fine.

Thanks A

Ironman

It appears that you’re leaking flue gasses into the cabinet and recirculating them back into the burner.

That’s a dangerous situation and should be corrected immediately.

A combustion analysis should also be done.

oki2oki

Thank you Ironman. I am getting combustion analyzer today so that i can tune the unit. Should i try to take off this silencer and try to see if it is seated properly?

Thanks A

oki2oki

Can someone with Bosch ZBR 28, or similar model help me with this?

Can someone please take a picture and show me how their silencer is connected on the bottom?

I was trying to push my silencer down and lock it so it doesn't go up and create this gap but i was not sure if this pin (red arrow pointing to it in my picture) or piece of plastic should be used to lock it or something. Seems like to be in my way or i am not doing it right. If someone can take a picture similar to mine and show me how it looks like on their side, i would really appreciate that.

Thanks A

Big Ed_4

Yes , that plastic tab lock locks in the muffler ..

oki2oki

I will take it off and then put it back. The way it is now I don’t think that tab is doing anything at the moment. And because of that, this is where I am getting the leak and boiler stopes working when cover is on.

kcopp

You need to call a professional who knows this boiler…

oki2oki

I tried but few companies I called and they asked me what boiler I have, they said I will call you right back and they never did. Seems like not many people in my area are familiar with this type of boiler.

Sukhoi29SU

Is it an “EA” error code? Where it requires you to reset it to get the boiler to fire off again?

I have a Bosch boiler I’ve been having occasional issues with. It’s an EA code - flame not sensed or detected.

oki2oki

https://forum.heatinghelp.com/discussion/comment/1872242#Comment_1872242

Yes that is what I am getting as well after day or two. I will have to reseat silencer properly and then I will use the analyzer to tune it.

oki2oki

https://forum.heatinghelp.com/discussion/comment/1872242#Comment_1872242

Can you please take a picture of bottom connection of your silencer so I can see it how it looks like in your boiler?

Thanks A

Ironman

Where are you located? We may be able to recommend someone.

oki2oki

https://forum.heatinghelp.com/discussion/comment/1872316#Comment_1872316

I am in Union NJ

EBEBRATT-Ed

@EzzyT, @clammy , @JohnNY

Sukhoi29SU

I’ve gotten the boiler pulled apart. I’m actually in the process of replacing the heat exchanger. It was tough to get any sort of customer support as the homeowner. Unless you’re a licensed technician holding a phone right in front of the boiler, they are reluctant to give any info whatsoever. When I said I was having trouble finding any reps in my area, they gave me a number to a place over 75 miles away in Chicago that doesn’t service my area, either. To be quite honest I had a lot of difficulty finding anyone who works on residential boilers in general, let alone these Bosch boilers. I finally found a licensed guy about 30 minutes away who contacted Bosch on my behalf. He said it was the most painful experience he’s ever dealt with as a technician , but after numerous phone calls , people pointing fingers and making it someone else’s problem, he finally found someone to help get this thing covered under warranty.
I understand your struggles

oki2oki

https://forum.heatinghelp.com/discussion/comment/1872346#Comment_1872346

And reason why i went with this boiler is because I read somewhere that owner perform maintenance and it is very easy to work with. But now it seems opposite.

Thank you for providing this picture. When you go ahead and installed it, can you then take another picture so that I can see how it is this sitting on your end? This tab that should lock this silencer, for me it is just not lining up at all.

oki2oki

Update.

I reseated silencer by pushing it down as much as possible so that seal is there. Then using analyzer i tuned max and low gas as per manufacturer specs. After that i closed the boiler with cover. It is working now fine for few days. I didn't get any code or anything so far.

Thanks A.