Utica mac150

seelman

Anyone have a utica mac 150 issues? I have a never ending problem on a 2 year old boiler keeps locking out on e53 which states blocked flue. Flue is not blocked and went as far as changing to a 2 pipe system to eliminate the chance of flue gas recirculating with air intake.

Ironman

You need a competent tech on site with proper instruments. You can't diagnose modern equipment by guessing or getting generalized answers. It might be something simple. Might not.

We're the installation instructions regarding venting followed correctly? Has the burner been checked with a digital combustion analyzer? The gas pressure? Did they give you the results?

seelman

Oh thanks that’s real helpful didn’t realize I was incompetent since I’m the person that installed the unit. And I do have all the proper equipment and when everything checks out and you call the service tech line and there pulling straws out of a hat to tell you what they think is the problem isn’t real helpful.

pecmsg

seelman said:

Oh thanks that’s real helpful didn’t realize I was incompetent since I’m the person that installed the unit. And I do have all the proper equipment and when everything checks out and you call the service tech line and there pulling straws out of a hat to tell you what they think is the problem isn’t real helpful.

WOW

JUGHNE

How about picture of the flue connection/inlet at the boiler?
I had this problem on FAF and found a simple solution.

Tim McElwain

If I am not mistaken that boiler has the automatic adjustment of combustion. If that is the case with what you are getting could be a contaminated air supply. I would suggest getting the factory involved as this problem occurs from time to time and they can walk you through the fix. I would also make sure the gas pressure into the unit is good somewhere around 6" W.C. pressure or more.

seelman

Factory has been uncool since problem started that why I converted it to a 2 pipe system instead on concentric vent so there no way of cross contamination. And the gas valve on this unit is negative pressure but the incoming pressure is 12 inches water column

seelman

Involved not incool

EBEBRATT-Ed

Is it possible wind or some other issue is causing flue gas recirculation even with the venting correctly installed?

Maybe some picture if possible the more eyes that look at this the better the chance of someone spotting something

DZoro

Lp gas? if so was it field converted or factory?
What size and type of gas pipe?
What size and length of venting?
What are your combustion numbers?
What did the heat exchanger look like when it was cleaned?
What is the gas pressure when in operation?

Tim McElwain

12 inches water column pressure is it propane? If it is natural gas that is a little high for an inlet pressure. If it is natural gas is there a regulator at the meter?

Tim McElwain

Which negative pressure valve is on this unit?

seelman

Sorry don’t have a picture of the venting but the exhaust goes out one side of the house air intake draws from uproars side of the house. Yes it’s propane and this boiler coverts itself after it does a combustion test . I don’t have exact numbers off the valve to give you that answer but venting is only 12 feet and gas line is 3/4” black iron directly to the unit gas line is 15 feet.

DZoro

The exhaust and intake are on the same side of the home and are approx. 18" apart? Exhaust higher than intake?

seelman

No exhauast is on the south east side and intake is on the north west side

DZoro

With that arrangement the wind will fool the boiler. One pipe will have positive pressure on it, and the other will have negative pressure. Thus sending a false alarm to the boiler, but the boiler doesn't know that it is false.
Put them on the same side as per the instruction manual.
That way the wind pressure will always be the same against both the intake and the exhaust.
D

Ironman

seelman said:

Oh thanks that’s real helpful didn’t realize I was incompetent since I’m the person that installed the unit. And I do have all the proper equipment and when everything checks out and you call the service tech line and there pulling straws out of a hat to tell you what they think is the problem isn’t real helpful.

I didn't say you were incompetent, but the way you worded the post lead me to believe you were the homeowner asking for help and my answer was to find a competent hydronic contractor. There are few of them that know how to service a mod/con.

Now you post that the venting instructions weren't followed. What are we to think?

seelman

Well there direction say that vent and air intake can be on opposite sides of the house so what am I suppose to think.

Erin Holohan Haskell

Guys, this looks like a simple misunderstanding. Please be respectful of one another and let's move on.

superdave

send Photos of unit on venting and the boiler its self. I think it is a Baxi boiler with a rebrand on it. You might need to put it in test mode and check it with combusting analyzer and did you check the Heat sensor it sends power back to PCB board. That is if its a Baxi rebrand.

seelman

I can send photos when I get back to that job. It’s is a baxi rebrand ecr international bought them out. Did not check sensor.

DZoro

I see they do allow that. I have seen issues with that arrangement with other brands. So I make it a policy not to do that or horizontal concentric venting. Just my personal preference.
How does the H/E look? Any small black grounds? Any possible blockage? Has it been cleaned out?
Does the gas pressure hold solid when running above 10in?
D

Ironman

Have you checked the condensate drain? If it's not draining properly, it will cause that code.

Rsnvhst1

How to set the temperature from the factory default on a Utica Mac 150 . Factory is 120 client wants 140 . I did inform about scalding water .