TT Prestige Solo 60 E02 ERROR

SunnyDay

Hi. My TT Prestige Solo 60 is 10-ish years old. A year ago it was going into E02. I replaced the ignitor. Worked well during warm weather, but recently going into E02 more frequently and in November E02 all the time. 

1. Confirmed ignitor is sparking well. 

2. Confirmed control module sending 26.9V to the rectifier cable. Disconnected the cable and received the appropriate error code for that too. 

3. Confirmed gas pressure is 10.5 in h2o. I measured pressure with an analog gauge at the IN (positive) screw of the gas valve. 

4.  Confirmed condensate is clean and draining. 

5. No change in design for the fresh air intake and exhaust pipes. Both are free and clear. 

6. Using the TT boiler troubleshooting guide, I replaced the gas valve and rectifier cable. 

7. The Venturi was soot covered. I cleaned it with isopropyl alcohol. I noticed the outboard side of black plastic Venturi (where the o-ring is located) was degraded and broken - a small
piece of plastic along the rim was missing. 

I’m not sure what my next steps should be. Based on research…

A. Should I replace the Venturi? 

B. Should I open up heat exchanger and clean it? Could there be blocked? 

C. Other options? 

The local HVAC guys are booked out solid. I have a background in being curious and CX’ing building systems, so I feel confident I can fix this! Luckily, the boiler is used only for DHW. Thanks! 

Zman

Do you know if a combustion analysis was ever done? Soot on the venturi or a pitted venturi is a sign of poor combustion or the exhaust and combustion air comingling (exhaust getting sucked back into the boiler). You do need a combustion analyzer to properly change the venturi.

SunnyDay

Hi Zman. I don’t have a recent CO analysis. That’s my bad! I recently purchased a Bacharach CO analyzer to service the boiler myself once the E02 issue was resolved, but the boiler won’t fire because of the E02 error. I’m wondering if 1of4 relays on the control board could be bad? Thanks for your feedback. 

Big Ed_4

This is not an home owner repair boiler . You need tech support , And tech support will not work with homeowners on repairs. It may be difficult to find a tech to work on them . But I recommend that you find one .....

kcopp

If the venturi is damaged its toast. Very sensitive.
It does not come factory pre-set.
You most certainly will need some tech guidance to set this up and get it running well.
Its really a job for a professional.

SunnyDay

Hi Big Ed and KCopp. The Venturi is definitely not “pristine” as described in the TT FAQs. I’m going to order a new one from Suplyhouse.com. Do you think in addition to that, the control
board relays could also be an issue? I’d hate to have to spend $571 for a new board. 

I have a Bacharach Fyrite Insight and digital
manometer and I know how to use them to adjust for O2 and CO2 as well as measuring differential pressures. I’ve been commissioning huge hvac building systems for 5 yrs. I totally respect hvac contractors, but I can’t find one in my area who isn’t booked out solid. So, I want to be self sufficient. The TT Solo 60 is not complicated. Thanks! 

Ironman

What, in the course of proper diagnosis, has lead you to believe the board is bad?

GGross

If the venturi is damaged it needs to be replaced. When the venturi is replaced combustion must be setup using a digital analyzer, you cannot skip this step the unit will not burn correctly. Damaged venturi will lead to improper combustion which will lead to failed ignitions giving you the E02 code.

If your boiler serial number starts with PT (looks like this https://cdn.triangletube.com/getmedia/70784fe5-12ae-49da-8dcb-98a8d468920a/Prestige-PT.jpg ) then there is a known ignition issue and an upgrade kit needs to be installed. Call tech support if you think your boiler needs the upgrade to confirm, the upgrade kit includes a board, transformer, igniter, flue pieces to get out of the cabinet, and new burner insulation

Big Ed_4

Even when I have a feeling it could be an expensive control. I like to bounce it off of tech support to make sure . You are in the field give them a call .

tim smith

To clarify 1st, this is not a newbie/homeowner job. This is for a gas burner mechanic. Taking apart and putting back together can cause unsafe conditions unless you have experience doing so or at least have someone instructing you with appropriate knowledge.

I with out a doubt would pull apart boiler and clean 1st. Just cleaned one yesterday that had not been cleaned in 7 yrs. Combustion chamber had a lot of coffee grounds in it and tubes were give or take 50% blocked. This definitely will cause sooting of venturi etc. Too much back pressure in combustion chamber. I can't recommend you do this yourself but as you commission hvac systems, you have general knowledge. Hopefully you can find someone who has done them several times and can take care of or at least help. Below is what most of them look like after 2-3 years. They show all the grounds on top of the tube sheet but they don't mention that they do drop into the tubes and can't pass the dimpling that is present at 3 or so locations down the length of the tubes. This stuff does not break down easily with any cleaner/ safe acid I have found. This is a mfrs photo of b4 and after cleaning.

SunnyDay

Ironman…I don’t believe it’s the control board. However, having the part on hand would be convenient. 

GGross. The boiler SS is PS71067. The recall doesn’t apply. 

Big Ed. I called TT tech support. They suggested replacing the Venturi (en route) and removing the blower and HEX cover the clean it out. However…have you seen the one Philips head screw mounted on the backside of the blower UNDER the motor shroud? Impossible to access. And, how do you get the HEX top off without damage to the seal? 

Tim Smith. Agreed. I measured gas pressure out the outlet side of the new valve during pre purge. It was 0. TT tech support said the Venturi (which is sooty and degraded) needs to be replaced and the HEX needs a proper cleaning. 

SunnyDay

I removed the blower/burner. See burner as found and HEX before/after vacuum. I used compressed air on the burner to get any residual dust off. IMHO these components are clean. Thoughts? 

SunnyDay

Based on Triangle Tube tech support the major issue is a degraded Venturi. So….picking the unit up tomorrow. Triangle Tube should emphasize this in their troubleshooting guide. Alas, getting closer to fire! 

Big Ed_4

Seems like you are on the right track ....

Zman

What do the terminations on the outside of the house look like? Are they the correct distance apart and on an open wall rather than a nook or inside corner? Just thinking about what may have caused the issue.

SunnyDay

Big Ed. Hopefully on the right track. Getting the Venturi today. Will post a conclusion. 

Zman. The intake and exhaust are along a north facing wall, no nearby corners or obstructions, free of internal blockage and protected with SS hardware cloth. I agree with you RE: finding out what may have caused the issue. The boiler was experiencing E02 a year ago. I replaced the ignitor, everything worked well. 9-10 months later, again the E02, resetting the boiler until it worked and eventually stopped working due to E02. To be fair, the boiler hasn’t be serviced for 5 years. Installed in 2010 and used primarily for DHW backup (we have solar thermal DHW) and seasonal lower level walkout basement heating. So…shame on me for not servicing the boiler - at minimum doing an annual combustion analysis. Perhaps…the boiler started burning too rich (the Venturi was soot covered), creating an erratic flame, incomplete combustion and….not sure. Thoughts? 

GGross

I would say that replacing the igniter fixed a symptom of the problem, not the cause, this is why it failed again more quickly. The soot covered venturi (which more importantly you mentioned was degraded and possibly had a hole) is the smoking gun. The soot doesn't come from just anywhere, it is coming from flue gasses, which are more than likely coming in to the venturi through the fresh air intake.

Ironman

GGross said:

I would say that replacing the igniter fixed a symptom of the problem, not the cause, this is why it failed again more quickly. The soot covered venturi (which more importantly you mentioned was degraded and possibly had a hole) is the smoking gun. The soot doesn't come from just anywhere, it is coming from flue gasses, which are more than likely coming in to the venturi through the fresh air intake.

^^ ^^

This, or there’s some chemical in the air nearby that’s being drawn in. Those are the only likely causes for the venturi to deteriorate.

One other possibility would be something in the propane.

SunnyDay

All. I installed a new Venturi. The boiler fired right up! Did a combustion analysis at High and Low fire, using the average min/max values for O2 (3.7%) and CO2 (11.3%). Glad to say the boiler is running well. The TT troubleshooting guide would have an individual replacing the ignitor (a consumable), rectifier cable and gas valve, but never mentioned inspecting the Venturi. Of course, this is the first time I’ve got into a boiler (matter of necessity). Anyhow, I hope this post helps someone in the future. I know I’ve read a lot of the forums to find the information I need!