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Combustion Analysis Lochinvar Epic 150 btu

robtheplumber
robtheplumber Member Posts: 5
edited November 17 in THE MAIN WALL

Hey Guys!

I had a gas contractor come over to my house and perform a combustion analysis test to possibly help me solve a flame fail running lockout and a flame fail ignition lockout. He opened up the flue port and started his readings. My boiler was out of the target range. After adjusting the gas valve we were able to get closer to target but never bang on. He mentioned that most boilers allow access with a computer to really fine tune the flame. I have the Lochinvar epic 150 (I'm pretty sure thats the Canadian version of the noble) they look identical anyways. I don't see a sync port anywhere. I'd love to get my boiler dialed in to hit the targets lochinvar is recommending. Has anyone heard of this procedure for the EPIC ? Is there a trick to hitting the targets?

A little bit of history: I am not a hydronic heating or gas guy, but I am fascinated by it. I did this install myself and I've always had ignition issues(I never did a combustion test). Sometimes the boiler fires and works no problem, and sometimes I have to press the reset button 3-4 times before it fires. Recently, the lockouts have been driving me crazy. We did a gas pressure test when the gas tech was at my house. I have 7 in w.c. at the boiler, I can't recall if we did a pressure test when the boiler was trying to fire. He sized my gas line 1" 30ft. and said it was more than big enough, so I don't think it's a lack of gas. I ran 2" venting/ air 15' with 3 90s and 1 45 so I don't think it's a venting/air issue.

I read on here someone was having same issues as me and said if they disconnected the clear tube that goes from the air inlet, and blow in it, it would help the boiler fire. I tried it on mine and it also made the boiler fire. This is what makes me think I need to dial in my combustion and the boiler will be fixed. Or is it possible debris somehow got stuck in the gas valve and now it just doesn't want to open and close properly? Someone please help me pin point whats going on here. My gas contractor wasn't satisfied and is willing to come back and do another test. I would really appreciate any information or tips on this!

Comments

  • HVACNUT
    HVACNUT Member Posts: 6,331

    If CO2 and O2 are out of Lochinvar spec even with has valve adjustments, then a call to Lochinvar is needed. Just have all the numbers ready.

  • robtheplumber
    robtheplumber Member Posts: 5

    Thanks for the reply! I'll give them a call with my gas guy present

  • GroundUp
    GroundUp Member Posts: 2,111

    It probably doesn't help that it's piped wrong and 10x oversized for the load, but the burner is very likely dirty after running it with the combustion all goofed up and needs to be cleaned. Gas pressure drop while trying to fire will confirm whether or not gas supply is adequate. How close were you able to get with the combustion, and what do you mean that you weren't able to get it "bang on"? Did you run out of adjustment with the screws or what was the issue, exactly?

  • robtheplumber
    robtheplumber Member Posts: 5

    agreed the burner needs to be cleaned, Its scheduled to be done early this week. Im almost positive we did a gas pressure test at ignition and the drop was still over the min. 4in w.c. I'd have to ask for the report to give the exact numbers. I dont recall them exactly. We ran out of screw before the target. and by bang on i mean the manual gives ranges with a exact target number. we didnt reach the target. how do you know its oversized for the load? and how is the piping wrong? the infloor heating and dhw works perfectly. my issue has to do with the boiler firing. once the boiler is firing everything works as it should… if you can draw on the picture or something i can make changes…. i had a friend in hydronics size the system for me before i did the work. i know that means nothing but thats what i went with. Is there anything i can do now? limit the boiler?

  • hot_rod
    hot_rod Member Posts: 23,385

    I think you need to get all the accurate data numbers before you call the tech support line. If you are going to make fine tuning adjustments you need meters connected.

    Ideally you would have all the meters connected while you are on the phone or face time call. Gas pressure manometer, combustion analyzer, VOM, for example.

    That boiler likes to be piped primary secondary or with a hydraulic sep. As per the manual.

    If you pipe full flow, like I think you have, you need to assure you have adequate flow when just a small zone calls, like that 3 port manifold.

    Check that Y strainer occasionally. The fine mesh inside gets partially plugged and causes flow issues.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • robtheplumber
    robtheplumber Member Posts: 5

    thanks for the reply hot_rod. I'll have it all ready when i make the call. Somethings off. Im starting to think its the gas valve… if i blow into or put my finger on the clear tube that goes from the air intake to the air valve the boiler fires. Does that sound like a symptom of a failing gas valve?

  • hot_rod
    hot_rod Member Posts: 23,385

    I'll bet the local Lochinvar rep or factory tech support have already been down this road. Many times no doubt. Youre missing something simple, I suspect.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • robtheplumber
    robtheplumber Member Posts: 5

    i hope so man… we'll see, i got my gas tech coming out tomorrow afternoon, ill post the results

  • GroundUp
    GroundUp Member Posts: 2,111

    It's piped wrong because there is no hydraulic separation- this is very clear in the installation manual. It's oversized because your only heating load is a 3 loop radiant system that'll only put out 30,000 BTU on a good day, ideally close to half that. Allowable pressure drop is only 1" WC from static. If static is 7" and it's dropping to 5, that's way too much and will cause exactly the symptoms you're seeing. Running out of adjustment is almost always a result of insufficient gas supply with these units. There is the very slight chance that the gas valve is misbehaving, but that's all but unheard of.